April 1982:space activities report

IUS UNITS DELIVERED

The first sections of the first Inertial Upper Stage (IUS) were
delivered by Boeing to the US Air Force’s Eastern Lauch Site
in Florida last December. The IUS will eventually serve as an
upper stage for both the Titan III and Shuttle vehicles, with
the first launch atop a Titan 34D this year.

The items delivered were the IUS’s equipment support
section with all its avionics and other systems, and the interstage which will connect the two solid-fuel rocket engines.

The equipment support section bouses systems for guidance
and navigation, telemetry, electrical power, tracking and command. It contains some 500 connectors and 4400 wires which,
in total, stretch almost five miles.

Redundancy and parts quality are the key to the lUS's
reliability, estimated to provide each vehicle with a 98 per cent
chance of success. For instance, the equipment support section
houses two identical master computers, each of which, in
addition to being capable of controlling the vehicle’s mission,
can isolate problems and circumvent them in milliseconds.

Other components which either have backup units or internal redundancy include guidance units, batteries, electrical
power buses, antennae, telemetry units, inertial measurement
units, signal conditioners and reaction control thrusters.

The two solid-fuel rocket motors, produced by the Chemical
Systems Division of United Technologies, were delivered later
for integration with the Boeing built segments to complete the
IUS.

SPACE TELESCOPE MIRROR COATED

NASA’s Space Telescope has passed a major milestone in
its development: the coating of the 94 inch primary mirror.

The Space Telescope, which will use two mirrors to focus
light from stellar objects on to a group of scientific instruments
at the rear of the telescope assembly, carries a 1800 lb primary
mirror coated with aluminium three millionths-of-an inch
thick.

The Perkin-Elmer Corporation, responsible for the design
and production of the optical assembly, completed coating the
primary mirror with the highly reflective metal on 5 December.

Engineers have since verified that the coating adheres to the
mirror and has the proper reflectivity.

A NEW SPACE LAUNCHER?

NASA is considering using some of the Space Shuttle’s
reusable features as part of an unmanned launch vehicle.
The Shuttle’s recoverable solid rocket boosters (SRB’s) would
make up the major segment of a launcher being studied by the
Boeing Aerospace Company.

Under a one-year, $250,000 contract with the NASA Marshall Space Flight Center, Boeing engineers are searching for
a concept that would use the Shuttle’s hardware and facilities
with only minor modifications. Called the SRB-X, the proposed
vehicle would use the solid rocket boosters, but not the Orbiter
or external tank.

Although the Space Shuttle will be the primary launcher, it
may need to share the load with another launch vehicle in a
mixed-fleet operation. NASA is considering this idea because
the Shuttle may have tight schedule requirements and payloads
that may be too large or heavy when delivered to certain
destinations.

The various SRB-X options being considered could deliver
payloads weighing up to 65,000 lb to low Earth orbit (about
150 miles) or 12,000 lb to geosynchronous orbit. SRB-X would
be tailored so that certain payloads could be interchangeable
with the Shuttle and could be launched from Shuttle facilities
at Kennedy Space Center or Vandcnberg Air Force Base. This
would allow for early availability and low developmental costs.

The contract with the space agency is divided into two study
areas. During the first six-month period, Boeing will study a large number of potential concepts using current or modified Shuttle boosters and selected upper stages. These concepts
will be compared in terms of performance, mission utility and
cost analysis. Upper stage and payload integration will be
considered as well as ground operations and facility require¬ments. By the end of the phase, the engineers will have
narrowed the field of options.

During the final six-month phase, the firm will define in
greater detail those particular concepts that seem most promising and make a final selection and recommendation. The
study results will then allow NASA to compare the recommended SRB-X concept with other Shuttle derived concepts.

KEY OF THE DOOR

At the conclusion of the STS-2 postflight press conference,
Astronaut Office Chief John W. Young presented ceremonial
keys for Columbia to the crew of STS-3. Jack'l.ousma described the mission of STS-3: “This time we will be up approximately seven days (116 orbits). And we will be doing essentially the same things that were done before but in addition there will be more work
with the Canadian-built arm (the Remote Manipulator System). We will actually be picking up some payloads, and we
have a really advanced scientific payload.’'

The payload known as OSS-1 (after the NASA Office of
Space Science) is mounted on a U-shaped pallet, making up a
2,609 lb package. A drum-shaped experiment will stretch 45
ft out from the cargo bay attached to the end of the flexing
robot arm. It will help engineers to discover just how rough a
wake Columbia produces in its journey through an ocean of
atomic particles.

The 4 ft-long box is part of a $20 million package of cameras,
probes and computerised dust-catchers.

Not all of the monitors of this experiment package deal with
inanimate atomic particles. Pilot Gordo Fullerton described the OSS.

“We have two payloads mounted in the payload bay, approximately 500 lb packages. We are planning to grapple those;
that is, grab onto them with a fixture at the end of the
manipulator arm, manoeuvre them to various positions outside
the payload bay taking scientific and environmental measurements and bringing them back and reberthing them in the
payload bay.”

Fullerton added, "In the launch and entry area we are going
to be expanding the envelope (by) flying a trajectory that is
more demanding on the vehicle and paving the way for heavier
payloads on later flights. And then during the re-entry executing additional manoeuvres to further understand the aero¬
dynamics and handling qualities of the Orbiter during that
phase of the flight. We will really be examining the full range
of the capability of the manipulator arm, although not with its
maximum capability.”

Commander Lousma provided an overview of crew activities
for the third orbital flight test: “We certainly plan to sleep as
much as required. But you find when you’re up there that you
have such a short opportunity to be there and you're not there
that very often it’s hard to go to sleep at night and you want
to look out the windows to see the spectacular view. And so
I think that some of the wake time is planned and some of it
unscheduled, but we plan to use a sleeping bag on this flight
and have one person sleeping at the controls. And we will try
to maintain a more rigorous schedule as far as eating and
sleeping are concerned. The second crew (Engle and Truly) told us that you had
to plan more time for getting the meals ready and handling
message traffic.”

One of the many television sequences planned for STS-3
includes an attempt to film the thrusters of the Reaction
Control System firing. John Young has previously described
the firing of the forward RCS jets as “sounding like a muffled
howitzer going off, with a blue flame shooting out about 40
ft.” Television planners hope to be able to capture the same
sort of sight if they are able to focus cameras on the systems.

NASA 1982 LAUNCH SCHEDULE

NASA planners have-an ambitious launch schedule for 1982:
12 expendable vehicle launches and three Space Shuttle flights,
including the first operational mission.

Of the 12 expendable vehicles, seven are Delta rockets,
three Atlas Centaurs and two Scouts. One of the Deltas will
be launched from Kennedy Space Renter facilities at Vandenberg Air Force Base, Calif., and will carry the only non¬
communications satellite to be launched this year.

The launch scorecard for 1982 began in January with
RCA-C aboard a Delta. February saw another Delta, this one
boosting Westar IV into orbit.

March begins with an Atlas Centaur rocket with the Intelsat
V F-4 satellite, and near the end of the month the third Space
Shuttle mission is scheduled.

April and May will have a Delta to launch lnsat-1A and an
Atlas Centaur for Intelsat V F-5.

In June, a Scout rocket will
launch\* a Defense Department Transit satellite from
Vandenberg.

July will have two launches: an Earth resources satellite,
Landsat D, aboard a Delta from Vandenberg, arfd the fourth
Space Shuttle mission (STS-4) from Kennedy Space Center.

In
early August Telesat F (also called Anik D), a Canadian
communications satellite, will be launched on a Delta rocket.

In late September, Westar V will be launched on a Delta.

November will see the fourth Delta in a row, with RCA E as
its payload, and will be highlighted by STS-5, the first operational mission of the Space Shuttle. That flight is listed as
carrying two communications satellites, SBS C and Telesat E,
and their boost stages plus an experiments pallet, OSTA-2.
The mission is scheduled to last five days.

Also in November, the year’s second Scout launch will orbit
San Marco-D/L, a joint NASA/Italy project designed to study
the relationship of solar activity to meteorological
phenomenon.

NASA will supply the launch vehicle while Italy supplies
the satellite which will be launched from Italy’s San Marco
launch site off the coast of Kenya.

The last launch of 1982 is now listed as an Atlas Centaur,
carrying Intelsat VA F-l, the third Atlas Centaur-Intelsat
combination for the year.

The Westars are being launched for Western Union, the
RCA satellites are part of the RCA Satcom Network, the SBS
series is owned and operated by Satellite Business Systems,
the Telesats are being orbited for Telesat Canada and the
Insat will be launched for India.