1

David	Lehman

September	7,	2021

Erik	M.	Conway,

Interviewer

Q: Okay.

Lehman: Your	audio	kind	of	breaks	up,	Erik.	It’s	sort	of	in	and	out.

Q: Yeah.	We’ve	had	bad	Internet	up	here	for	the	last	few	days,	and	so	it’s	not	a	thing	

I’ve	been	able	to	fix.

Lehman: Okay.

Q: So,	sorry	about	that.	We	may	have	a	good	bit	of	garbling	and	so	forth.	I	hope	not,	

but	we’ll	see.	I’ve	got	everything	else	closed	on	the	computer	except	Word,	so	I	can	

read	my	questions.	I	think	it’s	just	an	Internet	issue.

So,	first	off,	Dave,	how	long	were	you	at	JPL?

Lehman: How	long?	Over	forty	years.	November	3rd,	1980	is	when	I	started.

Q: Oh,	man,	the	day	before	my	birthday.	Very	good.	What	were	your	prior	projects	

prior	to	GRAIL?
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Lehman: Let’s	see.	I	worked	on	Deep	Space	1.	I	was the	project manager	of	Deep	

Space	1,	and	I	also	worked	on	Mars	Pathfinder.	I	was	technical	manager	of	one	of	the	

subsystems.	Let’s	see.	I	was	a	group	supervisor,	so	then	I	worked	on	all	the	projects,	

essentially.	That’s	about	it,	yeah.

Q: For	projects.	Okay.	And	let’s	see.	I	think	you	told	me	you	were	the	avionics	

manager	for	Pathfinder long	ago,	though.

Lehman: Right,	but	we	combined	two	subsystems	(Attitude	Control	Subsystem	and	

Command	and	Data	Control	Subsystem) into	one; it	wasn’t	called	avionics, but	that’s	

a	good	way	to	catch	it	now.	In	today’s	parlance,	it	would	be	called	avionics.

Q: So	tell	me	the	story	of	how	you	became	the	project	manager for	GRAIL.	It	was	

your	second	time	as	a	project	manager,	as	you’ve	said.

Lehman: Right.	Well,	the PI	was	Maria Zuber	during	step	one,	and	so	she	had	to	pick	

a	project	manager.	JPL probably gave	her	a	couple	names,	and	she	remembered	me	

because I	had	to	give	a	presentation.	When	Mars	’98	failed,	we	lost	those	two	

spacecraft,	NASA hired	a	committee	to	investigation	what’s	going	on	at	JPL,	and	

Maria	was	on	that	committee,	okay, investigating	JPL. So	I	had	to	give	a	presentation	

before	that	committee on	the	Deep	Space	One	project,	so	that’s	how	she	knew	me,	 it	
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was	just	that	one	presentation	that	I	gave	to her	committee.1 I	don’t	think	she	was	

head	of	the	committee;	she	was	just	a	member	of	the	committee.	So	that’s	how	she	

knew	who I	was.	So,	anyway,	so	she	picked	me.

But	for	GRAIL,	for	step	one,	it	was	very	late	when	they	finally	picked me,	so	

my	only	contribution	for	the	step	one proposal	was	just	submitting	my	résumé.	That	

was	it.

Q: What	time	frame	was	step	one for	GRAIL?

Lehman: I	don’t	know.	Let	me	think	about	that.	Time	frame	for	GRAIL for	step	one.	

I’d	have	to	think	about	that	one.

Q: Okay.

Lehman: GRAIL launched	ten	years	ago	this	coming	Friday.

Q: Right.

Lehman: It	was	9/10/11,	and	it’s	coming	up	on	9/10/21.

Q: So	the	step	one would	have	been	six	or	seven	years	before	that?

1 This	was	the	Mars	Program	Independent	Assessment	Team,	chaired	by	A.	Thomas	Young	of	

Lockheed	Martin,	March	14,	2000.
4

Lehman: Probably	like	five	years	before	then.2

Q: Five	years,	okay.

Lehman: I	can	look	it	up.	I	can	look	it	up	to	find	that.

Q: I	have	your	final	report,	so	I	can	probably look	that	up	too.	A	follow-up	question	

on	step	one,	though.	What	had	been	done	at	that	point?	I	just	want	whoever	uses	

this	again	to	understand what	is	in	a	step	one Discovery	proposal	versus	the	next	

step.

Lehman: The	step	one proposal	is	Discovery	puts	out	a	call	for proposals,	and	step	

one is	where	anybody	in	the	world	can	submit	a	proposal,	okay,	but	it’s	not	paid	for	

by	the	government, so	it’s	paid	for	by	the	institution.	So	JPL—I	don’t	know	how	

many	they	submitted.	I	think	when	GRAIL was	under	consideration	for	step	one,	I	

worked	on	two	others.	I	was	on	two	others.	The	ones	I	worked	on	didn’t	get	

accepted.	The	one	I	didn’t	work	on	did	get	accepted.	[laughs]

Anyway,	so	Maria Zuber,	she	was	the	PI,	and	her	deputy	PI	was	David	Smith.	

He’s	from	Goddard.	He’s	retired	from	Goddard.	But	Leon	Alkalai—you	know	Leon	

Alkalai?

Q: Yes.

2 Announcement	of	Opportunity	was	issued	January	3,	2006.	The	Step	1	proposal	was	submitted	in	

April	2006.
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Lehman: So	Leon	Alkalai,	he	was	the	proposal manager/capture	lead, and	I	think	he	

was	the	one	who	had	the	idea	for	GRAIL.	Basically,	GRACE	had	been	successful,	so	

really	the	idea	was	to	put	GRACE	at	the	Moon.	So	Leon	had	that	idea,	so	it	was	kind	

of	like	it	came	from	his	head.	And	then	he	had	to	get	the	PI	and	everybody	involved,	

okay,	but	that	was	the	main	thing	Leon	did,	was	creating	this	idea	and	bringing	in	

Maria	and	Dave	Smith,	and	then	Maria	hired	the	science	team.	So,	yeah,	what	was	

good	about	GRAIL was	the	step	one proposal was	excellent,	so	GRAIL had	an	

excellent birth,	okay,	and	it	was	championed	by	Leon	and	Maria.

Q: That’s	interesting.	I	didn’t	know	about	that	connection	to	Leon	Alkalai.	I’ll	have	to	

interview	him	about	that,	too,	just	as	I	have	to	interview	him	about	the	ventilator	

project.

Lehman: Yeah,	he	was	also	in	charge	of	step	two,	of	course,	too,	so	that’s	where	Leon	

and	I	worked	together on	GRAIL.

Q: So	would	he	have	been	the	capture	lead	for	step	two while	you	were	the	

manager?

Lehman: Yeah.	We	didn’t	call	it	that.	Back	then,	there	was	no	concept	of	a	capture	

lead.	It	was	just	called	proposal manager,	but	Leon	had	the	role,	what	we	would	call	

now	combined	capture	lead/proposal manager	for	both	step	one and	step	two,	for	
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both	of	them.	So	he	was	the	lead	guy	for	both	those	proposals,	step	one and	step	

two.

Q: Then	you	came	in	later.

Lehman: Yeah.	I	started	on	step	two.

Q: So	you	represent	the	transition.	You’ve	already	told	me	my	next	question,	which	

was	how	did	you	meet	Maria	Zuber.	You	met	her	when	you	did the	Deep	Space	One	

presentation.	So	tell	me	about	when	you	first	met	her	as	a	prospective	GRAIL project	

manager.

Lehman: Well,	she	called	me	and	asked	me,	and	introduced	herself,	“Hey,	I	was	on	

that	committee evaluating	Mars	’98	and	all	the	other	JPL projects,	including	Deep	

Space	1.”	So	then	we	met	over	the	phone.

Then	when	step	two happened,	then	we	started	having	daily	meetings	with	

Maria,	writing	the	step	two proposal,	so	that	was	mainly	all	done	by	the	phone,	and	

there	was	probably maybe	three	or	four	meetings	when	she	would	come	to	JPL or	

there’d	be	some	science	meeting,	like	the	DPS	[Division	for	Planetary	Sciences]

meeting,	or	the	meeting in	Houston.	What’s what	science	meeting in	Houston?

Q: The	Lunar	and	Planetary	Science Conference?
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Lehman: I	think	that	was	the	only	science	meeting they	had	during	step	two,	the	

Lunar	and	Planetary	Science	meeting.

Q: One	thing	that’s	always	interested	me	in	Discovery is	what’s	the	breakdown	of	

responsibilities between	the	project	manager and	the	PI.

Lehman: The	breakdown?

Q: Of	responsibilities.	Who	does	that	and	who’s	responsible	for	what?

Lehman: Well,	the	way	we	set	it	up	was,	see,	back	in	those	days,	did	you	hear	about	

Kepler	and	Deep	Impact?

Q: Oh,	yeah,	I	know	about	those	two,	yeah.

Lehman: Those	are	two	Discovery missions,	and	those Discovery missions,	they	

went	through	a	lot	of	project	managers.

Q: Yes.

Lehman: They	don’t	fire	PIs,	but	they	have	no	problem	firing	a	project	manager.	So	

my	idea	was	that—Maria,	she	said,	“My	goal	for	GRAIL is	to	come	up	with	the	best	

gravity	map	of	all	time	of	the	moon.”	And	she	goes,	“What’s	your	goal,	David?”
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I	said,	“My	goal	is	not	to	be	fired.”	So	that	was	my	goal.	That	was	my	goal	on	

GRAIL,	not	to	get	fired,	okay?

So	what	we	set	up	was	that	we	had	daily	tag-ups,	so	her	and	I	and	Dave	

Smith,	we	would tag	up—and	in	those	days,	Leon—the	four	of	us	would	tag	up	every	

day	so	we	knew	what	each	was	doing.	So	that	was	one	of	my	ways	not	to	get	fired,	

was	to	make	sure	that	we’re	both	in	the	loop.	If	you’re	both	in	the	loop,	you	know,	

you	can	decide	whatever	you	want	of	who	does	what,	but	mainly	she	was	in	charge	

of	gathering	together	the	science	team	and	putting	together	the	science section,	but	

she	kept	the	actual	proposal really	close	to	the	vest.	So	she	was	the	final	approval	of	

everything.	She’s	in	charge. I’m	just,	like,	her	assistant,	so	to	speak.

And	during	step	two,	the	proposal manager	and the	PI,	are	the	most	

important	parts,	the project	manager isn’t	that	important	at	that	time	because really	

my	only	output	was	to	have	the	management	section	done,	and	we	had	another	

fellow	do	that,	so	I	was	just	reading	everything	in	the	proposal.	I	wasn’t	a	writer.	I	

wasn’t	the	lead	author	of	any	one	section;	I	just	sort	of	reviewed	everything,	but	

especially	the	management	section.

So,	basically,	if	you’re	talking	to	somebody	every	day,	how	you	split	up	the	

labor	is	just	who’s	available	and	who’s	the	best	at	something,	so	that’s	how	we	set	it	

up.

Q: And	that’s	throughout	the	proposal process.

Lehman: Right.
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Q: Does	it	change	once	you’re	selected?

Lehman: Well,	then	the	proposal manager	goes	away,	so	Leon	left,	but	Dave	Smith,	

Maria,	and	I	continued	that	process,	daily	meetings	through	all	development	and	

through	operations,	daily	meetings	every	day.	I	would	basically tell	her,	“Okay,	this	

is	the	disasters	of	yesterday	and	this	is	what	we’re	going	to	do	today.	Any	

questions?”	[laughs] So	she	was	in	the	loop	with	everything,	and	she	was	in	the	

approval	loop	for	all	liens.	Any	expenditures	of	money,	you	know,	we	needed	more	

money	for	x,	y,	and	z,	she	was	the	approver	of	all	the	liens,	because if	you	know	

where	the	money	is,	you’re	in	charge.	That’s	different	than	most	project	managers	

on	Discovery.	Usually	the	project managers	are	in	charge	of	the	money.	In	this	case,	

Maria	was	really	in	charge	of	the	money.

Q: And	so	that sounds	like	an	interesting difference.	But,	man,	meeting everybody	

every	single	day,	I	assume	every	morning	or	was	it	in	the	afternoon?

Lehman: It	was	8:00	o’clock Pacific	Time,	and	she	was	there,	you	know.	People	

would	get	sick	or	go	on	vacation,	but	she	was	religious	about	that,	and	plus	the	

meetings	to	go	over	the	budget,	she	was	ruthless.	[laughs] Say	some	guy,	he	needed	

money	for	x,	and	he’d	have	to	prepare	paperwork	and	he	had	to	give	a	presentation	

to	Maria	and	Dave	Smith	and	I,	and Maria	and	Dave	were	ruthless.	So	it	was	like	
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their	own	money.	It	was	like	their	checkbook,	and	it	was,	because the	PI’s	in	charge	

of	everything,	especially	the	money	and	the	science.

Q: So	that	really	is	different	than	the	usual	JPL project	manager arrangement,	

because ours	tend	to	be	a	little	closed	with	what	they	share	with	people above	them.

Lehman: Yeah,	that	was	different,	and	that	was	all	part	of	me	not	wanting	to	get	

fired.	[laughs] I	didn’t	want	to	be	like	all	those	project	managers	on	Kepler	and Deep	

Impact.

Q: So	you	really	think	that	was	because they	just	didn’t	communicate	well?	Is	that	it?

Lehman: I’m	sure	it	was.	I’m	sure	it	was. You	know,	if	you’re	the	PI	and	you	find	out	

the	project	manager changed	computers	on	your	spacecraft,	“Whoa,”	you	know.	

“How	could	that	happen	without	me	knowing	about	it?”	I’m	sure	that	never	

happened,	but	something	drastic	probably would.

Q: Okay.	Interesting,	interesting.

Lehman: So	in	a	way,	Maria	was	the	project	manager and	I	was	the	deputy,	in	

essence.

Q: She’s	making	financial	decisions,	but	not	technical	ones,	right?
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Lehman: No,	no.	She	would	be	right	in	there	with	any	technical	decision.	She’d	be	

right	in	there.	She’s	be	right	in	there	with—you	know,	if	there’s	a	big	trade	study	

changing	out	a	gyro	or	something,	she	would	be	right	there.	She	would	hear	the	pros	

and	cons	and	the	decision	loop	for	that.	We	called	that	our	TSC Board. We	had	a	

Technical,	Schedule,	Cost	Board,	and	she	was	the	chairperson	of	that	board,	so	any	

technical	changes,	schedule	changes,	cost	changes,	she	was	the	chair	of	that	

committee of	three	people,	Dave	Smith,	Maria,	and	me.

Q: And	then	whatever	poor	engineer	that	needed	to	change	something,	it	sounds	

like.

Lehman: Yeah,	yeah,	yeah.

Q: So	was	this	TSC board	a	somewhat	special	purpose	thing	or	was	it	standard	and	

continuing	through	the	whole	project and	other	projects	too?

Lehman: It	was	a	special	purpose	group.	Most	projects,	they	call	that	just	the	Change	

Control	Board,	CCB,	but	we	just	had	a	different	name	for	it.	Typically	we’d	have	

those	on	Fridays,	because most	of	them	were	on	the	budget,	so	we	would	do	that	on	

Fridays,	but	they	could	be	ad	hoc.	If	something	has	to	happen	today,	we’d	do	it	

today.
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Q: And	you	didn’t	extend	that	membership	to	the	project engineer?	It	was	just the	

three	of	you?

Lehman: Just	the	three	of	us.	If	there	was	a	technical	lien,	then	the	chief	engineer	

and	the	project system	engineer	would	support	that,	but	that’s	very	rare.	That	was	

very	rare	on	GRAIL,	because Maria	and	Dave	Smith,	they	set	up	our	Level	1	

requirements.	They	never	changed.	They	set	it	up	in	step	one and	they	never	

changed,	so	that	was	something	that	helped	GRAIL,	was	continuity	of	requirements.

Q: You	didn’t	have	the	creep	that	many	projects	have.

Lehman: No.	Marie	and	Dave	Smith	were	ruthless.	Anybody	wanted	to	change	

anything,	forget	it.	Plus,	our	chief	engineer,	he	was	ruthless	also.	He	would	not	allow	

that	to	happen	at	all.	[laughs]

Q: Who	was	your	chief	engineer?	I	know	who	your	project engineer was,	but	who	

was	your	chief	engineer?

Lehman: Duncan	MacPherson.	He	passed	away	like	three	years	ago,	but	he	was	

really	good.	I	mean,	he	understood	the	science requirements,	and	he’s	the	only	one	

who	could	translate	those	into	what	engineers	can	understand.
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Q: Oh,	that’s	interesting.	He understood	the	gravity	stuff.	Because	some	of	that	is	a	

mystery	to	me.	Some	of	it	I	get,	but	some	of	it’s	just	a	mystery.	You	probably know	it

better	than	I	do.

Lehman: I	don’t	know.	It’s	pretty	tough.

Q: Yeah,	it’s	arcane.	So	let’s	see.	A	little	bit	back	to	the	proposal.	Do	you	happen	to	

know	what	the	other	missions	you	were	competing	against	were?

Lehman: No.	No,	I	can’t	remember.	I	was	the designated	project	manager for	two	of	

them,	and	I	can’t	remember.

Q: And	you	don’t	remember what	they	were.	Okay.	[laughter]

Lehman: Yeah.	If	I	can’t	remember those	two,	I	definitely	won’t	remember the	other	

ones.

Q: That’s	fine.	That’s	fine.	I’m	just	always	curious	about	what’s	the	competition,	but	

I’ll	bet	you	Maria	will	remember.

Lehman: Leon	would	know.	Leon would	know.

Q: Ah!	Okay.
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Lehman: Yeah,	he’s	the	type	of	guy	who	would	keep	track	of	all	that	stuff.

Q: Great.	Thank	you.	So,	let’s	see.	Next question	is	about	the	team.	So	tell	me	about	

assembling	your	team	once	you	win.	Who	do	you	put	in	the	major	roles,	and	why	did	

you	choose	the	people that	you	did?

Lehman: Okay.	Well,	during	step	two,	it	was	lucky.	At	the	time,	I	was	the	head	of	the	

Project	Support	Office.	Have	you	heard	of	that?

Q: Yep.

Lehman: Do	you	remember Tom	Gavin?

Q: Yeah.

Lehman: So	I	was	his	grunt,	basically,	and	so	I	was	head	of	the	Project	Support	

Office.	And	then	GRAIL came,	and	he	allowed	me	to	work	full-time	on	GRAIL.	I was	

on	burden	[funding] like	you,	and	so	I	worked	full-time	on	GRAIL for	nine	months	or	

whatever	it	was,	for	step	two,	and	my	focus	was	hiring	the	key	staff.	 So	I	put	a	lot	of	

thought	with	that,	you	know,	with	Leon	working	on	it	and	Maria	and	Dave	Smith.	So	

in	my	job,	there’s	like	maybe	five,	ten	people or	whatever,	the key	staff,	and	that’s	
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what	I	did,	was	to get	the	key	staff.	I	wasn’t	worried	about	writing	the	proposal so	

much,	but	getting	the	key	staff.	You	have	to	put	an	org	chart	in	the	proposal.

Duncan	I	brought	in.	Maria	and	Dave	Smith	and	Leon	already	[glitch	in	

recording],	so	we	brought	Duncan	in.	He	was	ordained from	the	beginning	because

they	knew	him	so	well.	Then	it	took	us	a	long	time	to	find	the	project system

engineer.	That’s	“Hoppy”	Price.	We	had	another	fellow—we	had,	like,	a	near	final	

meeting on	the	proposal,	and	this	guy	bombed	out	in	the	meeting,	so	we	had	to	

replace	him.	So	Hoppy	Price	replaced	him.	In	fact,	when	we	turned	in	the	step	two

proposal, Hoppy’s	name	wasn’t	in	it [laughs]	because	we’d	just	gotten	rid	of	the	

other	guy	just	before	we	submitted	it.

But,	anyway,	so	Hoppy	was	recommended,	and	then	both	Leon	and	Maria	

and	I,	we	all	concurred	on	that,	so	we	got	Hoppy,	and	he	worked	really	well	with	

Duncan,	because we’d	worked	before	that	on	Prometheus	with	John	Casani,	so	

Hoppy	was	on	there,	plus	Duncan.	They	were	kind	of	like	in	the	same	role,	the chief	

engineer and	project system	engineer.

Then	I	had	to	hire	a	spacecraft	manager,	so	I	interviewed	a	lot	of	guys	and	

talked to	a lot	of	people,	and	we	ended	up	with	Tom	Hoffman,	and	he’s	excellent.	

Now	he’s	project	manager of	InSight,	and	he’s	the	project	manager of	a	new	mission.	

I	can’t	remember what	it	is,	but	it’s	in	8X	now.

Q: Yeah,	I	remember his	name	coming	up	again,	but	I	don’t	remember what	the	

mission	is	either.3

3 NEO	Surveyor.
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Lehman: Yeah,	I	forgot	the	name	of	it.	Anyway,	so	Tom	was	excellent.	Then	we	had	

to	have	a	payload	manager,	and	that	was	Charlie	Dunn.	You	know	Charlie	Dunn?

Q: I	don’t	know	Charlie.

Lehman: He	was	the	payload	manager.	He	was	also	in	charge	of	the	instrument,	

okay,	and he	was	excellent.	He	had	been in	charge	of	the	instrument	on	GRACE.

Q: Right.

Lehman: So	he	just	moved	over	to	do	a	similar	instrument	for	GRAIL.	Then	we	had	a	

business	manager.	Her	name	was	Marjorie	Raymond.	She’s	in	9X	now.	Then	our	5X	

lead	was	Charlie	Bell.	Leon,	Maria,	and	Dave	Smith	were	in	the	loop	where	I	was

doing	this	hiring.

So,	anyways,	I’m	proud	of	that	because all	those	people stayed	onboard	until	

their	job	was	done,	so	there	were no	transitions,	okay?	To	me,	that’s	a	measure	of	‘I	

did	a	good	job.’ If	a	person	was	good	and	they	stayed	on—I	mean,	if	they	were	awful	

and	they	stayed	on,	that	would	be	bad,	but	they’re	all	good	and	they	all	stayed	on. So	

that	was	my	main job	in	step	two.

Then	Leon,	like	I	said,	he’s	the proposal manager,	but	he	was	also	

instrumental	in	getting	money	for	our	instruments.	During	step	two,	we	built	a	

prototype	of	the	instrument, the whole	thing,	and	so	when	we	had	our	site	visit,	we	
17

took	the	whole	review	team	up	to	the	mesa, on	top	of	the	hill	there	to	watch	how	the	

instrument works.	So	we	already	had	a	working	instrument by	the	time	of	the	site	

visit,	and	Leon	was	instrumental	in	getting	the	money,	and	then	Charlie	Dunn	was	

instrumental	in	getting	the	prototype	ready	for	the	site	visit.	So	that	was	really	

fantastic	that	they	were	able	to	do	that.	That	was	a	big	feather	in	our	hat,	the	site	

visit,	having	that	prototype	working	of	the	instrument.

Q: Do	you	think	that	mattered,	even	though—let’s	see.	By	the	time	that’s	going	on,	

GRACE	had	been	in	operation,	hadn’t	it?

Lehman: Yeah,	it’d	been	in	operation,	but	it’s	still	a	different—oh,	yeah,	it	had	been	

in	operation,	but	it’s	still	a	different	beast,	you	know,	different	frequencies.

Q: Oh,	I	see.	So	it’s	not just	a	copy.	It	was	actually a	different	instrument.

Lehman: Yeah,	it’s	a	different	instrument.	That	one	relied on	GPS.	There’s no	GPS	at	

the	Moon,	so	it’s	different,	but	it	was	very	similar.

Another	key	advantage	we	had	for the	site	visit	was	that	all	the	best	gravity	

scientists	in	the	world	were	on	our	proposal.	[laughter] I	mean,	when	they	did	the	

science evaluation,	there	was nobody	to	pick	[laughs]	to	evaluate	us.

Q: There	were	no	hostile	reviewers	available	with	the	right	competency.
18

Lehman: Right.	We	had	them	all,	okay?	So	they	didn’t	know	anything	about	our	

instrument.	All	they	knew	is	the	best	people in	the	world	were	saying	it’s	good,	our	

science is	good.	That’s	it.	So	they	really	couldn’t	give	us	a	thumbs-down	when	they	

didn’t	know	what	they	were	talking	about.	So	Maria	and	Dave	Smith	did	a	good	job	

finding	the	right	people for	the	science team.

Q: Very	cool.	Let’s	see.	Who	else	was	on	your	project team?	You	told	me	about	five	

people,	I	think?

Lehman: Let’s	see.	We	had	Marjorie—

Q: Duncan,	Hoppy.

Lehman: —business manager,	Hoppy	Price,	Duncan	MacPherson,	Tom	Hoffman,	and	

Charlie	Dunn.	We	had	a	chief	engineer for	the instrument,	and	this	name	was	Bill	

Klipstein.	Bill	Klipstein,	he	was	the	chief	engineer for	the	instrument.	Remember	

Deep—what’s	the	name	of	that	atomic—

Q: Deep	Space	Atomic	Clock?

Lehman: No,	no,	not	the	atomic	clock.	What’s	the	other	one?	The	laser	

communications.
19

Q: There	was	a	laser	communications	demonstration	on—was	it	on	MRO?

Lehman: No,	no,	no,	no,	no,	no.

Q: There’s	OPALS	in	Earth’s	orbit.

Lehman: No,	no,	no.	My	brain’s	not	working.	I’ll	remember it	in	a	minute.	Okay.	

There’s	Deep	Space	Atomic	Clock,	there’s	Deep	Space	using	lasers	for	

communication,	Deep	Space	Comm,	and	that’s	on	one	of	the	Discovery missions.	

What’s	the	name	of	that?

Q: I	don’t	have	any	memory	of	that. I’ll	look	this	up.

Lehman: Optical	Comm.

Q: Deep	Space	Optical	Comms?

Lehman: And	that’s	on	one	of	the	Discovery missions,	and	Bill	Klipstein	is	the	project	

manager of	that.	Deep	Space	Optical	Comm.

Q: Is	it	Lucy	or	Psyche?
20

Lehman: Yeah,	it’s	on	Psyche.	So,	anyways,	Bill	Klipstein,	he	was	the	lead	engineer or	

whatever	for	the	instrument,	and	so	then	he	graduated	to	become	the	project	

manager of	Deep	Space	Optical	Comm	on	Psyche.

Q: Interesting.	So	those	are	the	major	people.	Who	were	your	major	subcontractors	

and	how	did	you	choose	them?

Lehman: Okay.	It	was	Lockheed	Martin,	and	during	step	one,	Leon	did	some	sort	of	

evaluation	of	potential	contractors	and	they	picked	Lockheed.	So	that	was	done	

before	my	time. Then	the	project	manager at	Lockheed,	his	name	was	John	Henk.	

Yeah,	John	Henk. Then	the	lead	engineer,	their	chief	engineer was	Stu	Spath.	Stu	

Spath	eventually	became	one	of	the	super	head	guys	at	Lockheed.	He’s	since	retired.

Q: He’s	since	retired	too?

Lehman: Yeah.

Q: Don’t	know	that	I’ll	get	to	talk	to	either	of	them.	How	did	you	handle	

communications	with	Lockheed	during	the	project?	Were	they	part	of	the	daily	

phone	conversation	too?
21

Lehman: No,	the	daily	conversations were	just	between	Maria,	Dave	Smith,	and	I.	So,	

anyways,	so	I	hired	an	excellent	spacecraft	manager,	Tom	Hoffman.	He	took	care	of	

it.

Q: He did	that.	Okay.

Lehman: He	did	that,	and	that	wasn’t	my	job.

Q: That	was	in	his	portfolio.

Lehman: Yeah,	yeah.	But	during	development,	we	would	have	monthly	management	

reviews	at	Lockheed,	and	then	we’d	always	try	to	have	a	management	meeting just	

with the	managers.	If	Maria	was	there—well,	she	would	support	those	meetings	also	

with	Lockheed,	when	we	were	at	Denver.

Q: That	was	the	question.	So	when	you	were	out	in	Denver,	you	also	met	with	the	

management separately,	which	makes	sense.

Lehman: Yes.	Lockheed	was	great.	They	underran	the	project.	Yeah,	they	were	on	

schedule,	so	they’re	great.
22

Q: Now,	let’s	see.	There’s	still	another	management aspect	with	Discovery,	and	that	

is	you	have	program executives	at	headquarters	and	a	program manager at	Marshall	

Space Flight	Center.	So	talk	about	those	relationships	during	GRAIL.

Lehman: Okay.	Well,	what	we	did	is	we	would	have	weekly meetings	with	the	

Program	Office	at	Marshall	and	the	program	executive	at	headquarters,	and	so	in	

those	conversations	it’d	be	those	two	guys,	Maria,	Dave	Smith,	and	I.	So	those	were	

done	every	week.	It	worked	out	fine.	It	worked	out	fine.

Q: What	kind	of information	are	you	communicating	in	those?	Are	they	just	status	

updates?	I	mean,	I’m	sort	of	grasping	at	how	to understand	the	need	for	a	weekly	

meeting and	what	you’re	telling	them.

Lehman: You’re	telling	them	the	status	of the	mission,	but	basically you’re	always	

coming	up	on	a	next	key	decision	gate,	like	getting	ready for PDR,	CDR,	so	you’re	

going	over	the	status of	readiness	for	that,	all	right?	Like,	for	example,	a	PDR, that’s	a	

really	big	deal	for	a	project	manager to	get	ready	for,	so	you’ll	be	communicating	

with	them	on	the	status	of	all	the	products	that	are	due,	like	a	PDR	presentation,	and	

then	a	briefing	to	the	head	shed	[the	Director’s	Office]	at	JPL,	and	similarly	with	

headquarters.	The	program executive has	got	to	prepare	a lot	of	paperwork,	and	

then	that	guy,	he	would	work	with	the	Program	Office	to	get	that	done.	So	the	

Program	Office	is	really	kind	of	like	the	program	executives’	grunt.	They	get	stuff	

done.	And	whenever	there’s	some	kind	of	weird	headquarters requirements,	they	
23

would	try	to	buffer	it	so	it	would	have	less	effect	on	us.	So	they	would	try	to	end-run	

it	or	smooth	it	over	so	it	wouldn’t	cause	a	lot	of	turmoil,	or	hopefully	try	to	do	

whatever	they	needed	to	get	done	anyway.	So	the	Program	Office	was	very	helpful

in	that.

Q: So	you	saw	them	as	a	benefit.	You	saw	the	Marshall	office	as	a	benefit.

Lehman: Yeah.	The	Program Office	was	very good,	yeah.	It	was	Rick	Turner.	There	

was	three	of	them,	and	they	were	all	good.	Then	this	guy	Bill	Knopf,	he	was	the	

program	executive at	NASA	HQ.	He	was	very	good	too.	Bill	was	excellent.	Yeah,	I	

really	enjoyed	working	with	Bill,	all	of	them,	really.

Q: All	of	them.	So	sounds	like	you	had	a	largely	good	team	of	people you	had	to	work	

with.

Lehman: Yeah.	We	didn’t	have	any	mental	cases	at	all.

Q: No	real	problem	children.

Lehman: No.	So	we	were	blessed	at	the	beginning.	[laughs] When	they	picked	us	at	

end	of	step	two,	we’d	put	in	there	we	wanted	a	regular	Delta	rocket,	and	they	gave	

us	a	Delta	Heavy	rocket,	okay?
24

Q: Wow.

Lehman: And	so	that	was	really	nice	having	that	extra	mass.	[laughs] So	it	was	great.

Q: Yeah,	it	saved	you	probably a	lot	of	money	from	trying	to	shave	mass	off	the	

spacecraft.

Lehman: Yeah,	so	that	turned	out—like	I	said,	GRAIL had	a	really	good	birth

[laughter], Leon	writing	a	good	concept	and	then	having	an	extra	big	rocket.

Q: In	your	final	report—I	haven’t	read	all	of	it,	but	I’ve	read	a	lot	of	it	so	far—you	

complain	a	lot	about	reviews,	lots	of	excess	reviews	and so	forth.	So	my	first	

question	is	a	little	bit	historical.	What	do	you	think	was	the	trigger	for	all	the	

reviews?

Lehman: No,	it’s	just	normal.	All	projects	have	a	lot	of	reviews.	[laughs]

Q: So	you	didn’t	think	anything	had	changed	from	your	prior	experience,	right?	

Because	you	were	Deep	Space	1	project	manager.	So	did	you	think	your	review	

status	was	worse—

Lehman: Oh,	yeah.
25

Q: —or	the	same?

Lehman: Well,	Deep	Space	1,	that	was	during	“faster,	better,	cheaper,”	so	we	cut	

corners	on	everything,	but	what	we	did	on	GRAIL was	typical	of	a	Discovery project,	

but	it’s	still	a	lot.

Q: Still	a	lot.	You	mentioned	that	you	were	the	first	project to	operate	under	this	

NASA	Standing	Review	Board	requirement? Did	you	mean	the	first	project	at	JPL?	

Where	did	that	requirement come	from?

Lehman: Oh,	yeah.	See,	there	was	this	thing	called	the	NASA	Project	and	Program	

Management	Requirements.	I	can’t	remember the number	of	it.	[NASA	NPR	

72120.5]	Gavin	and	I	worked	on	the	latest	version	of	that,	okay?	Gavin	was	in	charge	

of	that. So	that’s	when	they	came	up	with	the	concept	for	the	Standing	Review	

Board,	was	in	that	document.	We	had	just	finished	writing	that	document	and	

getting	it	approved	by	NASA,	and	so	then	we	were	the	next	one.	We	were	the	first	

project after	that with	the	Standing	Review	Board	concept.	We	already	had	Standing	

Review	Board,	but	it	was	just	more	formalized.

Q: Oh,	I	see.	So	it	was	a	thing	that	already	existed,	and	you	altered	it	to	make	it	more	

formal.
26

Lehman: More	formal	and	with—I’m	trying	to	think	of	the	right	word.	More	formal	

and	it	was	more	independent.	I	mean,	a	JPL project just	couldn’t	pick	all	of—say	I	

was	a	project	manager and	I	wanted	to	have	a	Standing	Review	Board.	I’d	pick	all	

my	buddies.	[laughs] NASA didn’t	want	that.	They	wanted	more	independence,	so	

that	happened.	Cheryl	Reed, she	was	the	Standing	Review	Board	chair.	She	was	from	

APL.

Q: Okay.	Because	I	remember Tony	Spear	had	something	like	that [on	Mars	

Pathfinder],	but	it	was	Tony’s	people that	were	on	it.

Lehman: It	was	Tony’s	people,	yeah.

Q: So	that	was	a	self-inflicted	review,	I	guess,	in that	sense.	You	changed	the	terms	of	

it	to	make	it—well,	frankly,	more,	as	you	say,	more	formal	and	probably also	more	

reliable.

Lehman: Right.	Then	they	had	people on	the	payroll	to	do	cost	analysis	and	schedule	

analysis,	so	that	was	part	of	the	funding that	went	into	the	Standing	Review	Board	to	

actually fund	that	effort	to	do	more	independent	analyses.

Q: Okay.	Yeah,	that’s	good	to	know	and	interesting.	Let’s	see.	I	have	to	ask	this	

question.	Well	first,	what	reviews	are	actually under	the	purview	of	that	review	

board	versus	other	JPL in-house	sorts	of	reviews?
27

Lehman: I	would	say	all	the	reviews	that	are	before	a	gate	change, like	from	Phase	A	

to	B,	and	B	to	C,	the	Standing	Review	Board	is	the	review	just	before	you	change	

from	Phase	A	to	Phase	B.	That’s	a	gate	review,	okay?	So	that’s	a	whole	mission	

review.	But	then	all	the	reviews	for	subsystems	and	systems,	those	are	under	the	

purview	of	the	project	manager.	So	if	you’re	having	an	attitude	control	subsystem	

review,	that’s	under	the	purview	of	the	project	manager to	stand	up,	but	if	you’re	

getting	ready	for	KDP-C,	you	know,	you	have	to	go	in	front	of	the	Standing	Review	

Board	before	you	can	go	in	front	of	NASA to	say	you’re	ready.	They	have	to	concur	

with	that	based	on	the	review.

Q: So	this	is	probably a	dumb	question	because it	shows	you	how	far	I	am	from	the	

engineering	world,	but	what’s	the	relationship between	the	KDPs	and	the	things	we	

call	CDRs	and	PDRs?	Are	they	the	same	thing	or	are	those	just—what’s	that	

relationship?

Lehman: No,	no,	no.	For	KDP-C,	Key Decision	Point	C,	this	is	the	decision	point	to	go	

from	Phase	B	to	Phase	C,	from	preliminary	design	to	detail	design.	So	at	the	

assembly	level	and	subsystem	level	and	system	level,	you’ll	have	PDRs	at	a	low	level,	

okay?	And	when	you’re	done	with that,	then	you	have	the	big	one,	the	big	PDR	in	

front	of	the	Standing	Review	Board,	okay?	And	that’s	looking	at	everything,	not	only	

the	technical	stuff,	but	the	schedule and	the	cost. So	then	that’s	an	evaluation	by	an	

outside	group	of	whether you’re	ready	or	not	to	go	into	a	key	decision	point.
28

The	Standing	Review	Board	writes	a	report. Then	the	project gets	a	draft	of	

the	report	for	them	to	comment	on.	Then	if	they	say,	“Yeah,	you’re	okay,”	then	you’d	

have	to	go	in	front	of	the	Director’s	Office.	There	would	be	a	review,	okay?	So	you	

would	tell	them	their	status	so	the	director	knows,	yeah,	project	manager thinks	he	

or	she’s	ready	to	go.	And	Maria	would	be	in	that	meeting.	That	was	usually	led	by	

the	deputy	director,	so	nowadays	it would	be	Larry	James.

Then	if	you	get	the	thumbs-up	from	that	group,	then	the	next	step	is	to	get	

the	okay	at	the	headquarters level,	and	that’s	the	real	key	decision	point,	okay,	when	

you	go	in	front	of	headquarters.

So	then	the	program executive	working with	the	Program Office	at	Marshall,	

they	would	prepare	paperwork	saying	that,	yea,	verily, you’re	ready	to	go	into—

you’re	passing	this	Key	Decision	Point-C,	okay,	and	at	this	point	is	where,	the	KDP-C,	

this	is	where	you’re	officially	assigned	your	budget	and	your	schedule and	

everything.	Everything	up	to	that	is	preliminary.	In	fact,	you	remember Rick	

Grammier?

Q: Yes.

Lehman: He	was	the	head	of 4X	then, before	he	passed	away.	So	in	that	meeting with	

headquarters,	he	just	said,	“Hey,	I	think	they	need	another	10	million.”

“Why?”

“It’s	just	my	gut	feeling,	just	looking	at	all	this	stuff	and	this	and	that.	They	

need	another	10	million.”	So	we	got it	at	that	meeting.
29

So	the	head	of	the	Science	Mission	Directorate	was	Dr.	Ed	Weiler	at	the	time.	

He	said	“Okay.”	They	gave	us	the	10	million.	So	that	was	great.

At	the	time,	we	were	saying,	“We	don’t	need	it,”	but	we	really did.	[laughter]

We	didn’t	really	need	it,	but	it	was	nice	to	have	another	ten-million-dollar	buffer.

Q: Yeah,	to	add	into	your	manager’s	reserves.

Lehman: Yeah.	So	that	was	nice.	Rick	Grammier,	he	did	that.	That	was	a	key	thing	he	

did.	The	other	thing	is	we	had	a	cash	flow	problem	prior	to	that.	We	looked	in	the	

checkbook	and	we	needed	another	10	million.	What	are	we	going	to	do?	And	so	he	

was	able	to	get	10	million	from	the	rocket	transferred	over	to	us	temporarily	to	get	

us	through	this	cash	flow	issue.	So	that	was	the	two	key	things	Rick	Grammier	did,	

bless	his	heart,	for	GRAIL.

Q: Was	that	a	time	phasing	issue?

Lehman: “We	need	the	10	million	now,	but	we	don’t	need	it	later.”	That	was	all.	So	it	

wasn’t	an	overrun.	The	money	was	there,	but	in	the	future.	We	needed	it	now.	And	

the rocket	people didn’t	need	it.

Q: They	needed	it	some	other	time,	probably,	too.

Lehman: Yeah.
30

Q: They	needed	it	later.	[laughs] Okay.	So	still	on	the	subject	of	reviews,	how	do	you	

think	the	reviews	helped	you?

Lehman: How	did	they	help	us?

Q: Yeah.

Lehman: No,	there’s	no	help	from	a	review.	It’s	just	the	preparations	getting	ready	

for	it.	That’s	all	that	matters.

Q: So	they	didn’t	identify	any	issues?

Lehman: Well,	they	probably did,	but	usually	that’s	the	secondary	item.	It’s	just	

getting	ready	for	the	review	was	the	main	thing.

Q: Getting	ready	for	the	big	review	forces	you	to	carry	out	all	the	subsystem	reviews,	

and	that’s	when	you	find	things?

Lehman: Yeah,	yeah.	Everything’s	found	then.	I’m	sure	there’s	places	where	there’s	

good	advice,	but	I	can’t	think	of	any	right	now,	but	I’m	sure	there	were.
31

Q: Okay.	So	let’s	see.	Next	question.	Again,	in	your	final	report	you emphasize	

heritage	when	you	started	out	the	project,	because you	had	GRACE	heritage,	and	I	

understand	the	Lockheed	spacecraft	had	some	heritage	as	well.	So	talk	about	that	in	

your	flight	system	and	project.	How	did	that	heritage	argument	play	out?

Lehman: Well,	heritage	means	that	you’re	standing	on	the	shoulder	of	giants,	I	

guess,	trying	to	take	advantage	of	past	work,	and	so	that	worked	out	really	well	for	

us	with	the	GRACE	and	with	the	Lockheed	spacecraft	and	with	the	MoonKam	

instrument.	They	helped	in all	those	areas.	We	didn’t	have	to	do	new—the	amount	

of	new	developments	was	really	low.

Q: So	the	heritage	argument	was	meant	to	reduce	your	technical	risk.

Lehman: Right,	right.	I	mean,	if	you’re	using	the	engine	in	your	car	and	you	got	it	

from	an	engine	used	in	the	same	type	of	car	from	five	years	ago,	it’s	good.	It’s	the	

same	thing.	You	want	to	keep	using	that	engine	if	it	works	well.	[unclear] [00:47:44]

your	battery.	You	want	a	good	battery	from	the	past	car	for	the	future.

Q: You want	a	battery	that’s	recent	but	not	too	heritage,	because then	it	won’t	work.	

[laughs]

Lehman: Yeah,	yeah.
32

Q: They	do	have	a	limited	capacity. But	the	reason	I	ask	is	that	many	JPL projects	

start	out	claiming	a	lot	of	heritage	and	then	it	just	gets	washed	away	in	

development.

Lehman: Yeah,	so	we’re	lucky	with	Lockheed.	Lockheed doesn’t	allow	that.	I	mean,	

for	each	of	their	missions,	they’re	just	a	small	delta	from	one	to	the	next,	and	they	

just	slowly	do--whereas JPL,	they	just	go,	“We’re	going	to	just	change	everything	

here.”	Well,	they	have	to	make	a	profit,	you	know,	and	they	can’t	overrun	like	crazy.	

And	Discovery’s	very	sensitive	to	cost	growth	and	things.

Q: Yeah.	It’s	supposed	to	be	a	cost-capped	line	of	missions.

Lehman: Yeah,	yeah.

Q: Let’s	see.	You’re	also	one	of	the	earlier	projects	subject	to	the	new	Design	

Principles	and Flight	Project Practices.	So	did	those	impact	you?

Lehman: Yeah,	but	they’re	fine.	We	didn’t	have	any	problems	with	those.	We	didn’t	

have	any	problems.	They	were	good	guidance.	Yeah,	so	that	worked	out	well.

[unclear] [00:49:14].

Q: I	didn’t	mean	this	in	a	negative	sense	that	it	caused	you	problems,	but	I’m	trying	

to	get	at	maybe	the	opposite.	What	did	they	do	for	you?
33

Lehman: Well,	no,	no.

Q: Or	did	it	not	matter?

Lehman: They	were	good	guidance.	They	were	all	good	things	to	do.	We	had	very	

few	waivers.	I’m	trying	to	think.	We	had one	giant	waiver.	Can’t	think of	what	it	was.

Q: Was	it	from	single-string?

Lehman: It	must	have	been.	It	must	have	been	our	single-string	waiver	that	we	had	

to	get	approval,	but	there	was	another	waiver.	I	can’t	remember what	it	was,	but	we	

had	to	go	all	the	way	up	to	the	director. Dr.	Elachi	had	to	be	in	the	meeting.	It	had	to	

do	with	something	simple.	The	sentence	was	an	“and” or	an	“or.”	It	had	something	to	

do	with	you	need	to	test	it	this	and that.	We	did	this	or that.	It	was	something	really	

simple.	We	had	to	go	to	the	Director’s	Office	for	a	waiver	between	the	words	“and”	

and	“or.”	[laughs]

Q: Jeez.

Lehman: But	I	can’t	remember what	it	was,	but	it	was	funny	at	the	time.	“We’re	

going	to	the	Director’s	Office	for	this?”	It	was	some	test,	some	test	that	we	were	

doing.
34

Q: I	see. So	then	it’s	probably in	your	final	report	somewhere	and	I	just	haven’t	got	

to	it	yet.

Lehman: I	don’t	think	we’d	have	that	kind	of	detail,	but	there	was	some	test	where	

we	wanted	to	change	the	word	“and”	to	“or.”	[laughs]

Q: I	see.	Okay.	Let’s	see.	Last	question	for	this	interview	before	I	go	chase	after	some	

other	people.	What	would	you	say	were	kind	of	the	key	events	on	GRAIL,	from	your	

perspective?

Lehman: I	would	say	the	launch,	9/10/11,	and	the	final	day,	that	was	12/17/12.	

Yeah,	December	17th,	2012,	that	was	the	impact.	That	was	when	we	were	trying	to	

hit	Sally	Ride	Mountain,	okay,	and	that	was	really—that	was	something. [laughs]

Q: Well,	tell	me	about	it.	From	the	project	manager perspective,	it’s	a	little	unusual	

that	you	were	still	involved,	because a	lot	of	times	at	JPL,	the	project	manager during	

development	leaves,	but	you	didn’t.

Lehman: Yeah,	I	stayed for the	whole	mission.

Q: Tell	me	that	story.
35

Lehman: So	what	it	was	is,	okay,	Sally	Ride,	she	was	in	charge	of	our	EPO,	and	she	

had	passed	away	like	six	months	beforehand,	okay,	and	her	family	was	at	the	event	

when	we	were	doing	the	commanded	impact.	So	we	wanted	GRAIL to	impact	the	

Moon	on	not	the	far	side,	but	the	near	side,	okay?	And	we	wanted	to	impact—the

place	of	impact	we	wanted	to	call Sally	Ride	Mountain,	okay,	so	we	had	to	hit	this	

mountain.

The	problem	was	that	just	before	that	mountain	there	was	another	mountain,	

okay,	so	there	was	a	mountain	here	and	a	mountain	there,	and	we’re	coming	over	

this	way and	want	to	hit	this	one	and	not	this	one,	okay?	So	that	was	the	key	thing	

we	were	trying	to	do.	But	at	the	same	time,	we	wanted	to	do	an	experiment.	We	

wanted	to	determine	how	much	fuel	we	had	left	in	our	fuel	tank,	okay?	And	so	we	

did	a	controlled	burn	to	depletion.

So,	anyway,	so	we’re	coming	up	on	this	mountain,	and	at	the	same	time	we’re	

doing	a	controlled	burn,	okay?	So	how	are we	going	to	do	this	burn at	the	same	time	

we’re	trying	to	maintain	our	momentum	to	hit	this	mountain	and	not that	mountain,	

okay?	So	that	was	unbelievable.	Our mission	design	manager	was	Ralph	Roncoli.	

You	know	Ralph	Roncoli?

Q: I	know	the	name,	but	I	don’t	think	I’ve	ever	met	him.

Lehman: He’s	just	maybe	retired.	He’s	about	ready	to	retire.	He	was	our	mission	

design	lead,	so he	came	up	with	that	concept,	okay?
36

So	anyway,	so	that	was	a	pretty	key	event.	We’re	thrusting this	whole	time.	

We	don’t	want	to	hit	this	mountain,	but	we	want	to	hit	that mountain.	And	we	don’t	

want	to	go	on	the	far	side	of	the	Moon.	Otherwise,	we	didn’t	hit	anything.

I	forgot	one	key	person,	Erik,	and	that	was	our	mission	system	manager,	and	

that	was	Joe	Beerer.	He	retired	just	after	our	impacting	the	Moon.

Q: Right.	I	remember Joe. Not	sure	I	ever	interviewed	him,	but	I	remember.	Okay.	

And	no	other	key	events	then?	Just	the	launch	and	then	the	collision.

Lehman: Yeah,	those	are	the	key	events	for	me.	I	mean,	all	these	reviews	and

everything,	but	those	pale	in	significance—insignificance.

Q: Very	good.	Not	even	the	arrival	at	the	Moon?	Because	you had	a	somewhat	crazy	

trajectory.

Lehman: Yeah,	we	had	a	crazy	trajectory	to	get	there,	and	that	was	all	due	to	

minimizing—what	was	the reason	for	that?	First	of	all, we	wanted	to	have	the	orbit	

insertion	done	the	same	day,	regardless	of	the	launch	date,	okay?	Regardless	of	the	

launch	date.	That	was	kind	of	the	main	thing.	So	we	could	launch	thirty	days	later	

and	still	have	the	same	arrival	date,	okay?	Those	arrival	dates	were	like	January	1st,	

2012	and	January	2nd,	2012.

Q: Yeah,	they	were	only	a	day	apart.
37

Lehman: Yeah.

Q: I	would	have	thought	the	other	reason	would	be—but	I	don’t	remember this	from	

your	report,	but	fuel	savings,	because direct	ascent	trajectory	to	the	Moon,	you	need	

a	lot	of	deceleration	fuel,	I	would	think.

Lehman: That’s	another	reason,	is	reduced	fuel	usage.

Q: Since	you	have	to	carry	it	all.	Okay.	I	have	a	last	question	before	we	sign	off	that’s	

not	particularly	a	formal	one.	Do	you	think	Monique	would	be	willing	to	be	

interviewed	for	this?	One	of	the	questions	that	the	Discovery Program	manager	at	

headquarters asked	was	can	we	also	interview	families.

Lehman: Sure.

Q: To	see	how	the	family takes having	Dave	have	an	8:00	o’clock meeting every	

morning	for	four	years.

Lehman: Yeah,	I’m	sure	she’d	be	okay	with	it.	[laughter]

Q: Okay.	Then	I	can	do	that.	Maybe	it’ll	work	better	in	person.	Who	knows.	We’ll	see	

how	things	all	fall	out.
38

Lehman: Okay.

Q: Thank	you	for	your	time,	and	I	will	stop	recording.

Lehman: Okay.

[End	of interview]