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Minimalist upper stage as science probe missions serially produced

March 8, 2018

Minimalist upper stage as science probe missions serially produced, we are forced into the minimalist view at bottom of the page

ULA ACES without a docked spacecraft IE science instruments are carried on MOOG ESPA rings  and in the ACES intertank region, ACES does a burn to depletion at Pluto to slow to 2 to 3 miles per second to survey the unseen hemisphere of Pluto and Charon during a slow fly by

Does ACES at 7000 Kg dry mass plus 2000 Kg payload close to Uranus orbit Insertion?

From Elliot page 3 Elliott-Ice


Doppler Imager


Flyby/Orbiter <50 kg


Vis/NIR imaging spectrometer

Radio and Plasma suite

Thermal IR Mid-IR (Uranus) or UV (Neptune) spectrometer ~90 kg




Energetic Neutral Atoms

Dust detector

Langmuir probe

Mwave sounder/Mass spectrometer  ~150 kg

UO (no probe); 150 kg P/L 4718 kg wet spacecraft mass

Now let us subtract the spacecraft mass by using the Ice Giant study report and to add to the ULA ACES spacecraft bus those items beyond the components shared or replaced by ACES Avionics

Page 64 Ice Giant study report   Full-Report-Ice giants

Also mass and dimensions of instruments on the Oceanus study report

Oceanus study report

4718 kg – 2769 propellant = 1949 Kg I have rounded this up to 2000 Kg and added it to the 7000 Kg ACES dry mass plus instruments

worksheet (2)

We are down to 7.85 K/s which is below the required TUI injection speed but there may be some mass to allocate from the Uranus probe to the ACES

Altitude control  63.5 Kg &

Command and data  27.6 Kg are onboard the ACES

We must do a trade in regards to Uranus probe structures at 516.4 Kg which we have replaced with ESPA rings on the ACES  ESPA rings Can we save mass here? The ESPA rings would need to accommodate RTG and the 13 instruments as well as the communications antenna.One ESPA ring appears to mass 181 Kg.

Trades with ACES to do a lowest Neptune arrival V/A  Trajectory to Neptune

Elliot et all in the Ice presentation suggested that an ICE giant mission aerobrake at Titan(?) aerobraking, however, adds 20% mass back into the system as does our suggested hybrid cryogenic SEP propellent.Both ideas, however, pay for themselves in trades its hope. In an earlier post, we suggested that the foreword ESPA ring could house an inflatable HIAD and this serves a dual purpose in that it subsequently enters Titans atmosphere a second time to land.ACES to Ice giant could aerobrake at the destination and deploy its own HIAD to deploy atmosphere probes.Deploying atmosphere probes from ice giant orbit is cited above.deploying probes after entering orbit means you have modest EDL requirements as to heat.Indeed the program the decade survey says they need is called HEET.

perhaps due to costs the Elliot idea of hyperbolic in and out of Titan atmosphere but less so followed by a less strenuous aerobrake at the ice giant destination this might be the idea of the decade. This would not need HEET.

Imagine a 70 metric ton Ice Giant orbiter! Our original hypothesis was that we could get rid of the JPL/Lockheed Martin/APL deep space spacecraft, this is what the X team and Aerospace Corporation cost engineers at $4 Billion plus for two spacecraft.Our 70 metric ton spacecraft (wet) with the added on HIAD and cryogenic SEP systems would easily come out at this price unless we convinced ULA that a Cryogenic ACES became the standard model for the upper stage for cislurnar.after all we proposed in many previous blog entries that the launch contract pays for the ACES and the SMD pays for the “rest” still we need to now examine the same topic Elliot examines in the Virginia OPAG to costs Eliot Et al examines the flagship Neptune mission and a minamal Uranus flyby with just three instroments.flagship costs over $2 Billion Uranus flyby just over $1 Billion

So let us examine a ULA ACES minimal mission 🙂 It really depends on ULA leadership to mass produce for the cislunar economy the Cryogenic Xenon SEP system.(A)(1) the SEP system could be a small propellant tank that can deorbit any spent ACES stage or send it off into solar orbit.(A)(2) cryogenic Xenon would be an important component of a fuel depot so ACES is transporting Xenon around the inner solar system for prepositioning chemical propellants(Mars DRM 5.0) (A)(3) deep space ACES missions could refuel at a cislunar location(A)(4)SEP and Chemical SEP  both together needs a new mission design astrodynamics calculator***

If the above can be achieved then the next step would be to plan many flybys with atmosphere probes but we need to cost engineer the purchase of 4 to 5 sets of the $400 Million aerospace corporation cost engineered Ice Giant 13 instruments of choice and to do so with the options of the 50/90/150 Kilogram payloads.$400 million is for the 150 Kg so serially producing a flyby payload of say 90 Kg should be less plus the reduced cost of multiple purchases.

*** SEP Xenon propellant as an orbital debris mitigation effort paid for by the Air Force and NASA.(B)(1) The NASA NTR database has a 25 to 30-year-old paper on the idea of pressurized Xenon propellent tanks onboard a chemical upper stage/tanker/Tug, this concept could be scaled down to a transfer stage deorbiting demonstration mission.(B)(2)Transfer stage would need electrical power for several months for com/nav and the SEP engines so a non-deployable solar array is called for, this means we demonstrate another important capability all existing transfer stages(in GTO) can live for months until they achieve solar orbit or deorbit

SpaceX Falcon second stage


Blue origin second stage

(B)(3)ISS detached Cygnus could demonstrate orbit lowering /raising this way perhaps while still attached to the ISS?

(B)(4) It has been proposed that spent upper stages can be refurbished as habitats these to could have xenon propellant tanks for ISS or gateway maneuvering as an added value service to sell

(B)(5)The second goal would be to fire the SEP engine while still attached to the GEO bound payload as an added service.This would require larger xenon propellant tanks for the subsequent disposal to solar orbit

(C)(1)The third Goal is to repeat all of the above with Cryogenic Xenon cooled with a cryocooler or boiloff could this be done with a cryocooler only?


NEXTstep would be to mandate this for all GTO stages with the view that some economic value added comes with this capability (cislunar tug)and now we return to this economic utility of having it on our deep space probe.Some competitors faced with a requirement to remove the upper stage from orbit at end of mission might simply opt for a larger chemical upper stage

Recall that we have replaced the ACES com/nav and flight computer with JPL deepspace quality ones could these be serially produced for the cislunar tug? The price tag for one-off JPL deepspace com/nav and flight computer is in the $300 Million range so making this ACES standard equipment would be a challenge.

Do to costs it might make sense to utilize campaign of multiple ice giant flybys with the added bonus of Jupiter and Saturn flybys for atmosphere probe release.Two ACES would be Atmosphere probe deployers, We think each ACES could field three probes each.The first is a Jupiter flyby Neptune flyby with a probe for each planet and with the following payload


Doppler Imager


Flyby/Orbiter <50 kg


Vis/NIR imaging spectrometer

Radio and Plasma suite

Thermal IR Mid-IR (Uranus) or UV (Neptune) spectrometer ~90 kg

One probe with entry system masses at 300 Kg, so two probes could be 600 Kg plus a Jupiter Probe, would mass a lager entry system.Then add the 90 Kg instrument payload.  A Uranus flyby with ACES with a Saturn Flyby yields two-atmosphere probes for each planet plus another for Titan(1800 Kg).Saturn atmosphere probe is high on the decadal survey science requirements list.Both spacecraft could do the ARGOS mission that Dr. Amanda Zangari speaks about susequent to flyby.

Two spacecraft with 4 probes would be too heavy according to JPL to enter orbit so we propose three more spacecraft without probes that would enter orbit. 5 or more Vulcan/ACES should earn us a block buy discount but what about the instruments listed above? Having the orbiters in place first and a slow flyby could allow for backup probe data collection

JPL costs are high and seem to use Aerospace Corp and NASA cost engineering solutions some of these are in part based on past costs for past missions so it would be interesting to see if there are alternative cost engineering methods out there,ULA is attempting to improve its own cost engineering which is why we think their ACES might make for a reduced cost deep space probe.

As suggested in many previous blog posts we would allocate most of the ACES com/nav and flight computer to the NASA launch costs and not the AO mission caps.The deep space avionics would replace the ACES mission avionics to save on mass and costs and to justify the above idea.Most likely deep space antenna is attributable to the mission AO as are the ESPA rings, instruments, cabling,

ACES as a NASA launch vehicle provider is by definition TRL 6 and beyond by 2024

Minimal missions with ACES and 90 Kg of flight instruments purchased serially could allow NASA to stretch out the purchase and launch dates for 3 to 6 outer planet missions  based on a common spacecraft and with the ARGO concept could drop atmosphere probes and visit many an SBAG world

I think ACES ESPA ring probe is no more than $1.25 Billion for one certainly for 4 or more spacecraft.Perhaps this concept as a Neptune orbiter with 150 Kg of instruments beats the $2.6 Billion flagship costs quoted by JPL team X / Aerospace Corporation.

This blog post proposal should be read with the others as in this is a private/public partnership where a California Benefit Corporation owned by an ESOP has paid for the ACES ESPA ring deep space probe R&D with leveraged funds.ESOP retirees can not roll over or draw leveraged ESOP funds until the leveraged debt is paid off. ULA would refund the ACES  R&D that it paid for with interest over 20 years to the ESOP and the ESOP purchases spacecraft afterwords to sell as sovereign sales, its unlikely we can do this through the AO process
















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