SpaceX, NASA Misled Public About First Commercial Resupply Flight
Falcon 9 launches on its first commercial resupply mission.
As SpaceX prepared to launch its first commercial resupply mission to the International Space Station in October 2012, there was a rather curious aspect about the mission. While the Dragon spacecraft was advertised as being able to carry 3,310 kg of cargo, the ship was only loaded with 450 kg of cargo — less than 14 percent of maximum capacity.
SpaceX and NASA, which was paying for the flight, had an answer for that question at a press conference on the day before the Oct. 7 launch.
However, both NASA and SpaceX attributed the low mass to the selection of cargo it’s carrying. “The cargo up that we’re taking is not quite as dense as some of the cargo that we will be taking on successive missions,” said SpaceX president Gwynne Shotwell at a pre-launch press conference on Saturday. She added that SpaceX’s CRS contract with NASA requires it to carry at least 20 metric tons of cargo to the station over 12 flights; she estimates that SpaceX will carry a combined 60 metric tons up to and down from the station on those missions.
This answer does not appear to be entirely correct, however. Yes, the flight certainly carried cargo with less mass; however, the shortfall had nothing to do with the bulkiness of the equipment and supplies being sent up. Instead, it reflected the limitations of the SpaceX’s booster and supply ship at that time.
A NASA Inspector General report published in June found
The first two missions carried smaller loads because the empty cargo vehicles were heavier than expected and the Falcon 9 rocket did not meet its planned lift capability. SpaceX has since addressed both of these issues with an upgrade to its Falcon 9 rocket.
With the exception of SpaceX’s first two missions (SPX-1 and SPX-2), which delivered 450 kg and 865 kg to the ISS, respectively, NASA has generally loaded Dragon 1’s pressurized module to its volumetric limit.
The small cargo loads on the first two flights put SpaceX behind on its contractual obligation to fly up to 20 metric tons of cargo to the space station, although the company later reached that total on the eighth flight. The loss of the seventh resupply mission in June 2015 when its Falcon 9 rocket exploded in flight destroyed 2,478 kg of cargo worth $118 million. Under its contract with SpaceX, NASA must pay for the replacement and re-flight of that cargo.
NASA and SpaceX also experienced mass shortfalls on other Dragon flights due to limits packing limitations and a shortage of cargo for the spacecraft’s unpressurized trunk. SpaceX has become better at packing the Dragon with supplies. The shortage of equipment for the truck also has been addressed.
NASA has extended SpaceX’s Commercial Resupply Services 1 (CRS-1) contract, ordering eight more flights for a total of 20. The contract also has been extended until the CRS-2 take effect in 2019.
SpaceX and Orbital Sciences Corporation (now Orbital ATK) were awarded CRS-1 contracts. NASA awarded CRS-2 contracts to both companies and Sierra Nevada Corporation that run from 2019 to 2014.
28 responses to “SpaceX, NASA Misled Public About First Commercial Resupply Flight”
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Well that certainly helps to explain the aggressive upgrade strategy that SpaceX is executing on the Falcon 9. Apparently V1.0 turned out to be less powerful than originally planned/advertised?
I think the original advertised numbers were lower than what they’d internally planned. The alternative is that their upgrades were even bigger than we thought.
However, note that CRS-1 was also carrying a secondary payload. Dragon wasn’t mass-limited, it was under by at least the mass of the satellite (150 kg plus any other mounting hardware). And how can you say anyone was mislead when the manifest is clearly listed in the press kit?
http://www.nasa.gov/pdf/694…
It’s odd that while the amount of cargo carried was low that SpaceX carried a secondary payload that required a second burn of the upper stage. That burn didn’t take place because one of the first stage engines shut down prematurely.
The amount of cargo carried to station was listed in the press kit. However, when the media asked why the amount was so low, NASA and SpaceX said it was due to the cargo selected for the mission. However, the IG found that it was due to an under powered rocket and overweight spacecraft. So, the explanation was misleading.
The second commercial Dragon mission also had a low cargo mass. That flew on the final Falcon v1.0 launcher. The next Dragon flight was the upgraded Falcon v1.1.
I wonder if this has anything to do with why the payload attach fittings have much lower mass capacities (3453 kg for the light one and 10,886 kg for the heavy) than the listed payload capacities for the launcher. Add that to an apparent problem with various structural components on the vehicle and I wonder if there’s some mechanical under-design in the second stage. At least one of the two failures falls into that category, and the second failure has something to do with the second stage as well.
Could be nothing, but it got my antennae twitching.
It would seem to clarify some of the reasoning for their aggressive Merlin upgrades. Incidentally that upgrade program is one of the driving factors for the FH delays.
So the under performance of the v1.0 has surely been covered by the vast overperformance of the FT. NASA is still going to have a problem with the unpressurized trunk, they can’t seem to maximize the usefulness of that payload section. It’s a large volume and can hold considerable mass
Yes, the shortfall seems more due to a failure to take advantage of the spacecraft’s upmass capabilities than a failure to provide capacity, except for the first two flights, which were clearly said to be lightly loaded with relatively expendable supplies. And they’ve also compensated with their downmass capabilities, and with capabilities such as refrigeration and power supply for the return cargo.
SpaceX delivered less payload than they should have for the first series of missions. They are in fact still behind on their total upmass for the entire contract. All the other useful aspects of dragon are probably what allowed NASA and SpaceX to negotiate other compensation and what not.
I still don’t think low density consumables are the reason for the low upmass early on, it appears to be booster performance short falls
Since Dragon is the only way for NASA to return (reasonable quantities) of experiments and equipment to earth, I’m sure NASA took this capability into account when negotiating with SpaceX.
I agree but I think it’s been a way to renegotiate the early under performance. NASA is happy with getting their stuff back but I get the impression they are a little frustrated with the upmass numbers
This is all exclusively from memory, so take it with a tiny grain of salt (it’s all true, but don’t take the numbers as absolute gospel… not that you ever should with an internet comment:P):
The original paper version of the Falcon 9 was suppose to able to carry 12 tonnes to LEO. By the time the F9 Block 1 (now called the v1.0) actually launched, the expected performance had dropped to ~8.5 tonnes to LEO.
The Block 2 – which was never launched – was suppose to be able to carry just over 10.3 tonnes to LEO, and would have used the Merlin 1C+. However, all v1.0 launches were Block 1. Block 2 never made it to the pad.
Instead, the F9 v1.1 was developed. It could carry ~16 tonnes to LEO, although this was advertised as 13.5 with an unspecified (at the time) amount held in reserve for powered landing tests.
Next came the F9 Full Trust (or v1.2). It could carry ~20 tonnes to LEO in fully expendable mode. It has since been slightly uprated a couple of times. Probably due to them being able to examine the landed first stages and see what parts were over-designed and could have mass cut off of them. Also, they could look at actual flown engines and saw that they could be run at a higher thrust than they had previously been rated for.
Old news beaten to death so often and yet like Lazarus, appears yet again.
Oh well, must be a slow news day. 🙂
Cheers
I knew that the original Falcon had performance issues. This is really the first I’ve heard that the Dragon was overweight. I suppose it is easier to add booster performance than try to trim excess weight from Dragon. I wonder how much heavier the crew Dragon is over the cargo Dragon.
The FAA’s Environmental Assessment for the Firefly testing program listed the Dragon v2 test article weight at 14,100 lb.
Still a lightweight compared to Orion with its service module at 56,985 lb (according to Wikipedia).
It is smaller and doesn’t have a service module, so that stands to reason.
https://pacoarnau.files.wor…
Nice info-graphic.
The internal volume numbers are interesting, but largely irrelevant, IMHO. Since these are all pretty much “taxis”, they’ll be docking to (or landing nearby) their respective HAB modules. The HAB modules can be inflatable and provide far more internal volume than any capsule (capable of earth reentry land landing) ever could.
In a taxi role, CST-100 Starliner and Dragon V2 shine, since each can carry 7 passengers.
The low mass was written about at the time. And I did write about the issue a few months back when I did a deep dive into the IG report. However, this is the first time anyone has written that the explanation given at the time clashes with what the IG audit found.
The answer served the needs of NASA and SpaceX. Who wanted to admit that the system they had developed under COTS was under powered and overweight, couldn’t deliver the payload promised, and would require a significant upgrade not available until the third CRS flight to fulfill the contract? That wouldn’t look very good. And why were they flying a secondary payload on the first commercial flight if the mass carried by Dragon was so low? Another awkward question nobody wanted to answer.
Orbital ATK has had issues too. The original engines for their launch vehicle proved unreliable (resulting in the loss of one of their Cygnus cargo vessels). Hopefully their new Russian engines will work better than their old Russian engines.
Ah SLS Orion. The fallback position whenever faced with any criticism of or shortcomings in Musk, SpaceX or NASA’s commercial efforts.
This should, at the very least, raise the question of what else are they not telling us and will it take an IG audit to bring it into the light.
Its SLS that’s metal, and New Glenn and BFR that are powerpoint at this stage.
Being able to bring down mass capability probably saved them from harsher critical review?
Sounds likely. Cygnus has zero down mass capability. In the second round of commercial cargo, Dreamchaser should have down mass capability too.
Actually, I thought ESA isn’t flying ATV anymore.
And yes SLS plus Orion could do station resupply (launch with a MPLM in the payload adapter), but it would be an absolutely hideously expensive way to resupply ISS.
It would have been a cheaper way to build ISS though. Less modules, less fuss.
I’d love to see it launch the largest of the Bigelow modules there.
I’d just use a Falcon Heavy or Delta IV Heavy to launch a 20 ton Bigelow B330 module into whatever orbit you’d like. SLS not required.
I’ll still take that big shroud diameter.
But the point of an inflatable is that you don’t need “that big shroud diameter”.
Even inflates can take up space–especially the larger ones. And then there are scopes. I liked ATLAST–less moving parts than Webb.