Early days - carrier spacecraft (1/4)

There are a lot of people with a lot of ideas they would love to try out in space. Most of them will never get the opportunity under the current model; launch costs are too high, opportunities are too rare and profitability hasn't yet entered the equation unless you're a parts supplier.

 The recent trend of packing a set of small satellites (CubeSats, NanoSats, etc.) as secondary payload on other launches is helping. Colleges and private companies are getting their payloads into LEO and doing science. Most of that is aimed towards degrees and attracting research funding (or demonstrating experience and attracting investment capital); in other words, a short-term view with near-term goals. I don't think there is anything inherently wrong with the projects that have been selected so far, nor do I have any preferred pet projects that lost out. I just think the whole ecosystem needs to crank things up to 11.



 In support of that idea I worked up a description of a theoretical NASA program that would throw a huge number of cubesats into various interesting places. This is part of an overall narrative on what I think NASA should be doing over the next 15-20 years, but this piece stands alone (if unpolished). If anyone reading hadn't already noticed, I'm US-centric when it comes to space; if you would rather think of ESA doing something like this be my guest.

 Note that I assume a specific mass and volume scale based on CubeSats, but other scales are possible. I also had to assume that the deployment canisters massed as much as the satellites themselves, so a real implementation could be considerably more efficient than what I describe below at the cost of more $$$ spent on developing the carrier. Keep in mind that the Philae lander was less than 97 kg but my proposed carrier could bring 12 of them and still have room for a hundred 3U utility cubesats.

Carrier Satellite Program

The program centers on the use of carrier spacecraft equipped with numerous subsatellites. Subsatellites will carry commercial and academic payloads to perform research and design validation. Designs will be selected by committee and will include worldwide proposals. Carrier costs will be paid by NASA while subsatellite costs (including test, integration and launch fees) will be paid by each team. This architecture increases the number of instruments and technologies available for each mission while reducing the costs and spreading expertise among many commercial and academic groups.

The end goals of the program are a network of high-power comm relays to supplement the DSN, validation of ISRU / asteroid mining techniques, validation of on-orbit manufacturing and assembly, positioning the US launch services market as the primary provider worldwide, frequent launches with public involvement and improved interoperation with foreign space programs.

Subsatellite options:

Standard 6U/12U/27U launcher - 1 to 27 CubeSats each ($120-165k per U)

Extended 6U - 12kg / 10l single vehicle directly attached ($720k-$990k)

Extended 12U - 24kg / 20l single vehicle directly attached($1.44m-$1.98m)

Extended 27U - 54kg / 45l single vehicle directly attached ($3.24m-$4.46m)

Custom - Mission-specific custom designs replacing launchers mass for mass ($10k-14k per kg)

Carrier spacecraft:

Based on industry communication satellite bus, navigation, power

Separable into two independent halves

Full system-level redundancy for single mission

Phase 1 - LEO/GEO sweep

Carrier spacecraft will deploy and support many CubeSat payloads in low-Earth orbit, then split and ascend to GEO graveyard orbit for junk collection. Extended mission phase to EML-½ optional.

Objectives:

• Validation of swarm navigation and communication
• Validation of beamed power for subsatellites with high power needs
• Validation of separable carrier architecture
• Large-aperture antenna assembly in microgravity
• Demonstration of orbital debris cleanup / de-orbit in LEO
• Demonstration of graveyard satellite capture
• Demonstration of on-orbit repair and refueling tech
• Proof-of-concept deployable hydroponics

Launch service: SpaceX Falcon 9 (13.15t LEO, $61.2m)

Carrier spacecraft: 3.2x3.2x6.4m

(6km/s to GEO + 1.8km/s to EML-½ +1.4km/s margin (ion))

9.2km/s dV at Isp 4100 (NeXT) ~ 1.2572:1 = 10459kg dry

1380kg Xenon fuel

2430kg bus (2000kg), power (330kg, 18kW), tankage (100kg @ 7%), propulsion (3+1 NeXT)

2920kg payload:

160x 6U p-pods @ 12kg (8 wide x 5 high x 1 deep x 4 sides, 1920kg)

{0.404x0.247x0.167 (10 wide x 18 high x 1 deep x 4 sides = 720 max)}

500kg antenna / PV construction materials

500kg laser + science instruments

dry total: 5,350kg

wet total: 6,730kg

6,420kg launch margin (51.2%)

COTS-based satellite cost ~$150m

NASA systems: ~$100m

Launch: $62m (2018)

subtotal: $311.2m per flight

ground operations: $30m (1-year swarm @ $30m)

Phase 1 estimated cost: $342m less payload fees

~35% guest payload, ~ $125,000 to $135,000 per U, 960 U, $129m maximum

Results:

Baseline SEP tug / carrier validation

Deployable blanket thin-film PV experience

Deployable truss structure experience

Swarm communication experience

Orbital debris mitigation

Large assembly of defunct satellites for repair tests and repurposing

Phase 2 - Lunar shotgun

Carrier spacecraft will deploy and support many CubeSat payloads to EML-1/2/4/5. Carriers will provide four 10+ year multipurpose radio facilities for Earth communication relay, asteroid characterization, radioastronomy and other scientific uses.

Objectives:

• Validation of subsatellite technologies in the cislunar environment

• Split missions to EML-⅘
• Subsatellite return to Earth via 3-body trajectory
• Deployable hydroponics permanently stationed at EML-½
• Validate any phase 1 failures

Launch service: SpaceX Falcon Heavy (16t TLI, $150m)

Carrier spacecraft: 3.2x3.2x6.4m

(0.9km/s LOI (chem), 2.0km/s station + 1.0km/s margin (ion))

1km/s dV at Isp 324 (MMH/N2O4) ~ 1.37:1 = 11,678kg dry

3km/s dV at Isp 4100 (NeXT) ~ 1.0775:1 = 10,838kg dry

2300kg stable bipropellant fuel

500kg Xenon fuel

2650kg bus (2000kg), power (330kg, 18kW), propulsion (Aestus class/120kg/29kN, 1+1 NeXT), tankage (200kg @ 7%)

2920kg payload:

160x 6U p-pods @ 12kg (8 wide x 5 high x 1 deep x 4 sides, 1920kg)

{0.404x0.247x0.167 (10 wide x 18 high x 1 deep x 4 sides = 720 max)}

500kg antenna construction materials

500kg science instruments

dry total: 5,570kg

wet total: 8,370kg

7630kg launch margin (47.7%)

COTS-based satellite cost ~$150m

NASA systems: ~$100m

Launch: $150m

subtotal: $400m per flight

2 flights (EML-1 2023 and EML-2 2019) = $800m

ground operations: $50m (2-year swarm @ $25m, 10-year comm relay / radar observatory @ $25m)

Phase 2 estimated cost: $850m less payload fees

~35% guest payload, ~ $155,000 to $165,000 per U, 1,920 U, $316m maximum

Results:

1,920 U of subsatellites deployed to EML-1/2/4/5

Comm relays at EML1/2/4/5 (40-42m dia.)

Lagrangian point transfer experience

Lunar orbiter mission opportunities for any nation, university, corporation or group.

Phase 3 - Martian Moons

Carrier spacecraft will travel to Mars orbit, then split and deploy to Phobos and Deimos. Many subsatellites will be deployed and supported. Samples will be collected from multiple sites of each body and returned to the carriers, which will then return to Earth.

Objectives:

• Phobos and Deimos imaging, sounding, landings, sample returns
• Mars vicinity hydroponics performance

Launch service: SpaceX Falcon Heavy (13.2t TMI, $150m)

Carrier spacecraft: 3.2x3.2x6.4m

(0.9km/s MOI (chem), 0.8km/s per moon + 6km/s to Earth + 1km/s to LEO +1.4km/s margin (ion))

1km/s dV at Isp 324 (MMH/N2O4) ~ 1.37:1 = 9635kg dry

10km/s dV at Isp 4100 (NeXT) ~ 1.2824:1 = 7513kg dry

2400kg stable bipropellant fuel

1430kg Xenon fuel

2720kg bus (2000kg), power (330kg, 18kW/7.2kW), propulsion (Aestus class/120kg/29kN, 3+1 NeXT), tankage (270kg @ 7%)

2320kg payload:

160x 6U p-pods @ 12kg (8 wide x 5 high x 1 deep x 4 sides, 1920kg)

{0.404x0.247x0.167 (10 wide x 18 high x 1 deep x 4 sides = 720 max)}

200kg antenna construction materials (~38m dia.)

200kg science instruments

dry total: 5,040kg

wet total: 8,870kg

4,330kg launch margin (32.8%)

option: 530kg per Kuck Mosquito

COTS-based satellite cost ~$150m

NASA systems: ~$100m

Launch: $150m (2020)

subtotal: $400m per flight

ground operations: $50m (2-year swarm @ $25m, 20-year comm relay / radar observatory @ $25m)

Phase 3 estimated cost: $450m less payload fees

~38% guest payload, ~ $180,000 to $190,000 per U, 960 U, $182m maximum

Results:

960U of subsatellites delivered to Martian orbit and moons

ISRU/mining/benefication technology validation

Comm relay ~38m dia.

Deep-space SEP tug / carrier validation

Sample return 2023-2024 up to 580kg (1:1 packaging to samples) or 1,060kg (jettisoning p-pods)

Extensive observation of Mars and its satellites

Phase 4 - Captured NEO

Carrier spacecraft will deploy and support many CubeSat payloads to a captured NEO. Carrier will provide sample transportation back to LEO. This mission requires at least one successful asteroid redirect mission. Alternatively, mission could be sent to an asteroid or comet in place with reduced goals.

Objectives:

• Apply previous experience to ‘dissect’ an asteroid remotely

• Demonstrate extraction of volatiles, oxygen, metals
• Demonstrate basalt fiber production
• Demonstrate zone refining
• Deliver purified water, radiation shielding, bulk and refined samples to ISS / LEO
• Produce organic polymers via hydroponics
• Validate on-orbit manufacturing processes

Launch service: SpaceX Falcon Heavy (16t TLI, $150m)

Carrier spacecraft: 3.2x3.2x6.4m

(0.9km/s LOI (chem), 1.0km/s station + 1.0km/s LEO + 1.0km/s margin (ion))

1km/s dV at Isp 324 (MMH/N2O4) ~ 1.37:1 = 11,678kg dry

3km/s dV at Isp 4100 (NeXT) ~ 1.0775:1 = 10,838kg dry

2300kg stable bipropellant fuel

500kg Xenon fuel

2650kg bus (2000kg), power (330kg, 18kW), propulsion (Aestus class/120kg/29kN, 1+1 NeXT), tankage (200kg @ 7%)

2920kg payload:

160x 6U p-pods @ 12kg (8 wide x 5 high x 1 deep x 4 sides, 1920kg)

{0.404x0.247x0.167 (10 wide x 18 high x 1 deep x 4 sides = 720 max)}

500kg reflector construction materials, industrial reagents

500kg science instruments

dry total: 5,570kg

wet total: 8,370kg

7630kg launch margin (47.7%)

COTS-based satellite cost ~$150m

NASA systems: ~$100m

Launch: $150m

subtotal: $400m per flight

4 flights (2026-2030 depending on availability) = $1,600m

ground operations: $100m (2-year swarm @ $25m x4)

Phase 4 estimated cost: $1,700m less payload fees

~35% guest payload, ~ $155,000 to $165,000 per U, 3,840 U, $633m maximum

Results:

3,840 U of subsatellites deployed to one or more captured near-earth objects

Four 1200m² reflector, 1.6MWt solar ovens

Useful water and oxygen delivered to ISS / LEO for use

Useful radiation shielding produced for future manned missions

Produce useful structures entirely from in-situ resources

• overwrap composite tanks made from aluminum-coated basalt fibers
• thin-film silicon PV made from Earth or IS films and IS semiconductors
• structurally-stable radiation shield modules from sintered slag and wire

summary:

Program DDT&E: $800m (could be shared with carrier program)

Vehicles: $150m each, $1,200m total

NASA costs: $400m

Operations: $230m

Launch: $1,112m

Margin: $1,123m

Program duration: 2016-2031 (15 years)

Program total: $4,865m ($325m per year)

Recoverable payload fees - up to $1,290m (26%)

Alternate scenario: DDT&E drops by half due to cooperation with ARM program. Costs become $400m, $1,200m, $320m, $230m, $1,112m, $979m, total: $4,241m or $283m per year.

results:

8 carrier spacecraft missions

5 high-power radar installations

4 megawatt-class solar ovens / solar concentrators

Over a thousand subsatellites deployed near Earth and four other bodies

Phobos and Deimos sample returns

Extensive technology validation in several major fields:

• in-orbit assembly
• debris mitigation
• asteroid resource extraction
• in-orbit manufacturing
• swarm navigation and communication

followup:

full-scale solar panel factory at EML-½

full-scale asteroid processing facility at EML-½

satellite maintenance facility at EML-½

Phobos and/or Deimos excavation for habitat placement