"Space is big. Really big. You won't believe how mind boggling big it is. I mean, you may think it's a long way down the street to the Chemist, but....."You may think the two dimensional surface of the Earth is big but increase that from two to six dimensions and it gets really big.
There is no such thing as a "corral" for satellites and no practice al way to do" trash collection". Even if dispensed together they will disperse in all those dimensions.
There are NSF threads and conferences discussing that. It is not clear that this is on-topic for this thread about this particular launch.
I am afraid I may not have been succinct, the use of the word corral was not suggesting a paddock like arrangement, but simply of establishing a parametric boundary beyond which a satellite within the virtual 'corral' would not be permitted to stray. Of course those with no control will disperse, however since the sheep dog satellite does have control, it simply snags each one as it drifts out of control, and, once it has snagged all of them then they are all considered retired and then re-entered. People who make nano and micro sats that don't want them to have positive control, probably did not intend them to last very long.
Well the person I was responding to who thought that this sort of dedicated launch of potentially 100's of nano sats obviously thought that the threat was real.
Quote from: ChrisWilson68 on 10/01/2015 08:28 amThis is exactly why all those start-ups trying to build dedicated launchers for small payloads for $5-$10 million a shot are doomed to fail.maybe, maybe not Still the question I asked and had pulled. Why this launch in 2017 was costing $100 million dollars?That comes to $65 million launch costs & aprox $35 million processing. Where is the professed drop in price for reusable to $15 Million listed in many threads?The costs are not going down as advertised
This is exactly why all those start-ups trying to build dedicated launchers for small payloads for $5-$10 million a shot are doomed to fail.
Are satellites on the Sun Synch Express allowed to carry propellant and thrusters?Some primary payload customers restrict them.
the acceptance of the payload is subject to approval by the Launch Services Provider and Spaceflight
Satellite shall be in compliance with AFSPCMAN 91‐710 o Propulsion systems, if accepted, shall be designed, integrated and tested in accordance with Volume 3. Additionally, activation of propulsion shall have 3 inhibits. o Hazardous material shall be in compliance with Volume 3
The mission’s manifest includes satellites ranging from a 5kg 3U CubeSat up to a 575kg satellite.
We intend to offer annual missions to a low earth, sun synchronous orbit beginning in 2017 and to Geosynchronous Transfer Orbit (GTO) beginning in 2018
Blake said Spaceflight looks forward to using a previously flown Falcon 9 rocket in the future.
So, if we assume a typical 600-800km sun-synchronous target orbit (per Wiki) for the F9 upper stage, how hard is it to get from such an orbit to the Moon, and land? Assuming the 575kg payload is the SpaceIL spacecraft, presumably most of that is going to be fuel for the TLI burn, orbital insertion, and landing? Seems like very thin margins, which I guess is to be expected.Congratulations to SpaceIL on being the first Google XPrice competitor to sign a launch contract!
The team's lander, temporarily named "Sparrow," will sit in a designated capsule on the Falcon 9 rocket, among other secondary payloads. The rocket will deploy all other spacecraft aboard first, once it reaches lower Earth orbit — and Sparrow will be the last one off in the cosmic carpool. Once Sparrow is alone, the Falcon 9 will reignite the engine in its upper stage, carrying the lander a significant way toward the Moon. The lander will then detach from the rocket and propel itself the rest of the way to the lunar surface.
According to the Spaceflight Industries schedule it is a 500-600km SSO. More importantly the delta-V required may be significantly lower, however since only one of the many news articles covering this news story mentioned it, we may need to take this with a grain of salt until there is more confirmation:The Verge article on the SpaceIL announcementQuoteThe team's lander, temporarily named "Sparrow," will sit in a designated capsule on the Falcon 9 rocket, among other secondary payloads. The rocket will deploy all other spacecraft aboard first, once it reaches lower Earth orbit — and Sparrow will be the last one off in the cosmic carpool. Once Sparrow is alone, the Falcon 9 will reignite the engine in its upper stage, carrying the lander a significant way toward the Moon. The lander will then detach from the rocket and propel itself the rest of the way to the lunar surface. Of course this begs the question: "how much fuel will be left on the Falcon US?" and my guess is that depends on how many more payloads that Spaceflight Industries sells.
Surely someone on this forum can calculate the burn-to-depletion orbit given estimates of the combined mass of the satellites, "Sparrow", and the dispensing hardware, with either three or four burns.
Quote from: Comga on 10/07/2015 03:38 pmSurely someone on this forum can calculate the burn-to-depletion orbit given estimates of the combined mass of the satellites, "Sparrow", and the dispensing hardware, with either three or four burns.With or without first stage recovery - plus is it RTLS or barge? As well, what will the weight of all the satellites launched be? Spaceflight industries is continuing to sell space on that flight.
Are you volunteering?
More importantly the delta-V required may be significantly lower, however since only one of the many news articles covering this news story mentioned it, we may need to take this with a grain of salt until there is more confirmation:The Verge article on the SpaceIL announcementQuoteThe team's lander, temporarily named "Sparrow," will sit in a designated capsule on the Falcon 9 rocket, among other secondary payloads. The rocket will deploy all other spacecraft aboard first, once it reaches lower Earth orbit — and Sparrow will be the last one off in the cosmic carpool. Once Sparrow is alone, the Falcon 9 will reignite the engine in its upper stage, carrying the lander a significant way toward the Moon. The lander will then detach from the rocket and propel itself the rest of the way to the lunar surface. Of course this begs the question: "how much fuel will be left on the Falcon US?" and my guess is that depends on how many more payloads that Spaceflight Industries sells.
Has any Falcon second stage done three burns? (Inject, circularization, disposal?)
With the limited throttle range of the Merlin 1D-Vac, if the upper stage burns to depletion to perform TLI, with sparrow as the only payload, what will the acceleration be like?
Quote from: zt on 10/07/2015 07:11 pmWith the limited throttle range of the Merlin 1D-Vac, if the upper stage burns to depletion to perform TLI, with sparrow as the only payload, what will the acceleration be like?I believe the dispenser will also still be there, which is probably some not-insignificant mass.Still, you have a point -- SpaceIL will definitely need to make sure Sparrow can handle high g loads!