SAEVe: A Long Duration Small Sat 

Class Venus Lander

Seismic and Atmospheric Exploration of Venus

Tibor Kremic presenting on behalf of team: Richard Ghail, Martha 

Gilmore, Gary Hunter, Walter Kiefer, Sanjay Limaye, Michael 

Pauken, Colin Wilson, and Carol Tolbert

Approved for public release 1
Venus Scientific Goals

• Venus is in many ways Earth’s nearest sibling

– Almost same size as earth and probably still volcanically active

• Yet we know very little about it!

• Venus may have had a liquid water ocean for > 1 B years 

• SAEVe helps address high-priority science themes:

– How volcanically and tectonically active is Venus today?

– Why and when did the climates of Venus and Earth diverge?

2

https://www.nasa.gov/feature/goddard/2016/nasa-climatemodeling-suggests-venus-may-have-been-habitable

?

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http://www.planetary.org/multimedia/spaceimages/venus/venus-in-ultraviolet-from-akatsuki.html
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The Venus Surface Environment

• The Venus surface is challenging - Temperature = 460 °C, Pressure = 

92 bar, [supercritical] CO2 atmosphere

– Si electronics do not operate > 300 °C.

• Previous landers dealt with heat by being heavy (~1 tonne) and 

insulated; they lasted up to 2 hr before heat penetrated to their 

interior and destroyed the electronics

• Thick sulphuric acid cloud layers severely constrain remote sensing

• SAEVe uses unique new silicon carbide based electronics and 

sensors

– Can operate in harsh environments, in particular temperatures of 500 °C. 

3

SiC electronics and high temperature systems enable a new class of lightweight 

uncooled Venus landers; enabling > 103increase in surface lifetime.

Significant new science can be achieved !
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SAEVe Science

4

300 to 800 km

Decadal Survey Goals SAEVe Science 

Objectives

Measurements Instrument 

Requirements

A) Characterize planetary interiors 1) Determine if Venus is currently 

active, characterize the rate and style 

of seismic activity

Measure seismic waveform of 

seismic waves

Determine wind-induced seismic 

noise. Concurrent measurements 

with seismometer

3-axis (1 axis) seismometer

wind speed & direction sensors

2) Determine the thickness and 

composition of the crust

Same as above Two stations with instrumentation 

as above.

B) Define the current climate on 

the terrestrial planets

3) Acquire temporal meteorological 

data

Measurement of p, T, u, v and light wind speed & direction sensors, 

radiance

4) Estimate momentum exchange 

between the surface and the 

atmosphere

Same as above Same as above during Venus day 

and night

C) Understand chemistry of the 

middle, upper and lower 

atmosphere 

5) Determine the key atmospheric 

species at the surface over time

Measure the abundance of gases 

H2O, SO2, SOx, CO, HF, HCl, 

HCN, OCS, NO, O2

Chemical sensor measurements 

during descent and on surface

D) Understand the major heat loss 

mechanisms 

6) Determine the current rate of 

energy loss at the Venus surface

Measure heat flux at Venus 

surface

Heat flow measurements,

radiance, air temperature

E) Characterize planetary surfaces 7) Determine the morphology of the 

local landing site(s)

Quantify dimensions, structures 

and textures of surface materials 

on plains unit. 

Descent and surface images
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Courtesy: Tom Pike

MEMS seismic event sensor

Sensors images – Courtesy: NASA GRC

Heat Flux sensor - Courtesy: Mike Pauken

Courtesy of D. Makel, 

Makel Engineering, Inc.

The Instrument Suite

Rationale for Instruments / Sensors

A) Core science centers around long term 

measurements to obtain meteorological and seismic 

data over 1 Venus solar day (120 Earth days)

B) This is possible with high temperature, low power, 

low data volume instruments / sensors

• Instrument payload supports this constraint

Instrument set includes:

• A 3-axis micro-machined Micro-Electro-Mechanical Systems 

(MEMS) seismometer (0.3 kg)

• Meteorological sensor suite (temperature, pressure, wind 

speed & direction, solar radiance, atmospheric chemical 

species abundances), and solar position sensors (0.7 kg)

• Heat Flux instrument (0.3 kg)

• Two COTS Cubesat cameras (0.1 kg each)
6

Wind Sensor ( on top)

Pressure 

Sensor

Temperature 

Sensor

Chemical Sensors

Reflected solar 

radiance

Crush Pad

Seismometer (Shown 

dropped next to lander)

Wind Sensors

Sun position sensor

Solar radiance

Note: Antenna shown in image is backup approach using UHF 

Loop Antenna (1.5 m Circumference). 

Primary approach is planar spiral – 24 cm diameter

Drag Flap

Batteries

Avionics / PMAD

Instruments / payload Comm

Camera sphere

Note: Camera spheres and heat flux 

instrument not shown in this diagram 

for clarity

Heat Flux Instrument

21.4 cm

21.6 cm

48.1 cm

20.8 cm

23 kg Approved for public release

Lander Configuration
SAEVe co-launched with a Venus 

orbiter (integrated with orbiter 

through a spin-table)

Cruise to Venus 

~ 3-4 months

Orbiter releases landers at 7 rpm up 

to 30 days before entry 

Lander releases designed to provide 

appropriate separation on surface 

Orbiter Inserts into orbit. 

Assuming 24 hour at this time

Orbiter receives critical 

event telemetry and 

science data from 

lander through descent

Landers ‘wake up’ ~ 1⁄2 hr 

before entering Venus 

atmosphere and start 

transmitting critical data

Orbiter 

deploys UHF 

antenna

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The Mission
The Entry Sequence

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80 km

70 km

60 km

50 km

40 km

30 km

20 km

10 km

0 km Surface

Venus Atmospheric Descent

Subsonic Speeds 

are reached 20 s 

after entry

Shells separate 

releasing lander at 6 km 

Landers reach 

surface 62 min after 

entry

Lander provides UHF telemetry to Orbiter just before and during 

EDL

After turn on, landers 

transmit T&P telemetry 

as possible during 

descent to 6 km (inside 

shell)

Landers take nadir images 

at 5 km and 400 m

Landers take surface images 

of seismometer before and 

after deployment

Lander configuration inside 0.6 m entry shell

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Desired Landing Sites*

Desired landing site: flat area near potentially active sites 

Atla Regio and Beta Regio (black) and Lakshmi Planum (white)

* Will be heavily influenced by Orbiter trajectory and its initial orbit

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The Operations

• SAEVe will operate for 120 days or longer

• Communications and seismic monitoring are main energy users and 

hence, main limiters of lander lifetime

• Communications with orbiter is assumed to be for 2 min every 8 hr

– Actual timing and frequency will be negotiated with orbiter. Contact time over 

120 days could be as high as 93%

– Opportunities exist to extend life (e.g., with <2 min comm or more battery)

• When seismic event detected, lander will transmit data from all 3 

axis within 100 ms and continue for 10 min – regardless of orbiter 

location 

• For the first hour landers collect and transmit data from all 

instruments

– Get early, higher frequency data (provides some risk reduction)

• During mission multiple seismic trigger levels may be employed

– For example, a priori potentially decrease trigger level mid mission – ensure 

some events captured

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Science / Dollar Summary

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De-Scoped 

Lander

Science Objectives Tackled

1) Determine if Venus is seismically active and characterize the rate and style of activity, 

2) Acquire temporal meteorological data to guide global circulation models

3) Estimate the momentum exchange between the planet and its atmosphere

4) Measure atmospheric chemistry variability

5) Determine current rate of heat loss from the Venus interior 

One Lander 

6) Examine rock and soil distribution and morphology

SAEVe Science Ladder

Science Objectives Tackled

1) Determine if Venus is seismically active and characterize the rate and style of 

activity, 

2) Determine crust thickness and composition 

3) Acquire temporal meteorological data to guide global circulation models

4) Estimate the momentum exchange between the planet and its atmosphere

5) Measure atmospheric chemistry variability

6) Determine current rate of heat loss from the Venus interior 

7) Examine rock and soil distribution and morphology

Full Mission

$106M $87M

Science Objectives Tackled

1) Determine if Venus is seismically active and characterize the rate and style of activity, 

2) Acquire temporal meteorological data to guide global circulation models

3) Estimate the momentum exchange between the planet and its atmosphere

4) Measure atmospheric chemistry variability,

$71M

* Estimates do not include reserves or to get to TRL-6 for technologies
Technology Readiness

• Summary table shows that major subsystems and the instruments are 

currently at TRL 3-4 (lowest TRL components are seismometer & 

battery)

• Main take-away is that most elements of SAEVe are in ongoing 

development that will take them to ~ TRL 6 by 2021

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Technology Current 

TRL

Estimated to be at

TRL 6

Funding Source: Ongoing (O) (to TRL 6) 

and Potential (P)

Electronic circuits (SiC): sensors and data handling 4-5 Aug 2019 LLISSE (O)

Electronic circuits (SiC): power management 3-4 Sept 2021 LLISSE (O)

Communications (100 MHz) 3-4 Sept 2021 LLISSE (O)

Wind Sensor 4 Aug 2019 LLISSE (O)

Temperature Sensor 4-5 Aug 2019 LLISSE (O)

Pressure Sensor 4-5 Aug 2019 LLISSE (O)

Chemical Sensors 5 Aug 2019 LLISSE/HOTTech (O)

LLISSE Bolometer 3-4 Sept 2021 LLISSE (O)

Seismometer 3 TBD MaTISSE (P)

Heat Flux Sensor 3-4 TBD PICASSO (O) - MaTISSE

Camera / imaging System 3-4 Sept 2020 Rocket University (O) – MaTISSE if needed

Solar Radiance 4 TBD MaTISSE (P)

High-Temp Battery 3 Aug 2019 LLISSE and HOTTech (O)
Thank you. Questions? 

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SAEVe will revolutionize our paradigm for exploring the deep 

atmosphere, surface, and geophysical activity of Venus. This is 

enabled by new advances in high temperature electronics and systems. 

SAEVe will operate on the surface of Venus for an unprecedented 

120 days (full Venus solar day) returning seismic, meteorology,

and energy deposition / release data 

The SAEVe mission can be implemented for ~ $100M and would be an 

ideal candidate to ride along with a future Venus orbiter mission

SAEVe would serve as a pathfinder to prepare for larger 

and more capable landers in the future