I've heard that if one wanted to just have a spacecraft flyby Europa many times with no instruments, the cost would be about $1B. If you want to do great science, too, about double that price
According to this source(pdf), Cassini's scientific instrument cost was $200 million out of a $1.4 billion total spacecraft development budget.
Quote from: ncb1397 on 10/09/2014 03:10 amQuote from: Blackstar on 10/09/2014 01:21 amQuote from: redliox on 10/08/2014 10:18 pmI don't recall probes in the '60s and '70s opting for numerous out-of-the-way gravity assists, so I see them for what they are: improvising. You cannot simply throw a large launch vehicle at every mission. That's expensive. That is money better spent on instruments.Has anyone proposed doing something like using an HLV for every mission? Instruments are usually a small portion of a mission's budget. Launch vehicle size, and cost, has been a factor in the selection and non-selection of many planetary missions over the years. Look at Voyager-Mars as the classic example. Of course, size of the spacecraft (and cost) usually tracks with size of the rocket, but as a general rule, planetary missions have sought to keep the launch vehicle size as small as possible and mission designers are not automatically given the option of the largest rocket (there's a reason why Curiosity and Juno did not launch on Delta IVs, for instance).
Quote from: Blackstar on 10/09/2014 01:21 amQuote from: redliox on 10/08/2014 10:18 pmI don't recall probes in the '60s and '70s opting for numerous out-of-the-way gravity assists, so I see them for what they are: improvising. You cannot simply throw a large launch vehicle at every mission. That's expensive. That is money better spent on instruments.Has anyone proposed doing something like using an HLV for every mission? Instruments are usually a small portion of a mission's budget.
Quote from: redliox on 10/08/2014 10:18 pmI don't recall probes in the '60s and '70s opting for numerous out-of-the-way gravity assists, so I see them for what they are: improvising. You cannot simply throw a large launch vehicle at every mission. That's expensive. That is money better spent on instruments.
I don't recall probes in the '60s and '70s opting for numerous out-of-the-way gravity assists, so I see them for what they are: improvising.
Quote from: Jim on 10/09/2014 01:56 pmQuote from: ncb1397 on 10/09/2014 03:10 amInstruments are usually a small portion of a mission's budget. For instance, from memory, I think MSL was 2.5 billion total cost and the instruments were ~100 million total.Wrong. They are not a small portion. A lander is the wrong example. MSL had 3 additional pieces of hardware that other spacecraft don't have: aeroshell, descent stage, and rover.Also, the Curiosity instrument suite cost more than that. I think the cost was more like $170-$190 million. After all, the cost of the instrument suite for Mars 2020--not including the sample cacher--is over $130 million.
Quote from: ncb1397 on 10/09/2014 03:10 amInstruments are usually a small portion of a mission's budget. For instance, from memory, I think MSL was 2.5 billion total cost and the instruments were ~100 million total.Wrong. They are not a small portion. A lander is the wrong example. MSL had 3 additional pieces of hardware that other spacecraft don't have: aeroshell, descent stage, and rover.
Instruments are usually a small portion of a mission's budget. For instance, from memory, I think MSL was 2.5 billion total cost and the instruments were ~100 million total.
The 19-member SDT, headed by Brown University geologist Jack Mustard, has been told NASA will have about $80 million for rover science instruments, Meyer said, adding that at least one and possibly two more instruments, with a total value of about $20 million, also should be coming from participating international or other partners.
Although Curiosity’s initial budget for science instruments was $85 million in 2004 dollars, the agency ended up spending roughly twice that amount.
Quote from: metaphor on 10/09/2014 04:55 pmAccording to this source(pdf), Cassini's scientific instrument cost was $200 million out of a $1.4 billion total spacecraft development budget.$400M for the TIV, so 1/5 of the spacecraft cost.
Quote from: Jim on 10/09/2014 05:22 pmQuote from: metaphor on 10/09/2014 04:55 pmAccording to this source(pdf), Cassini's scientific instrument cost was $200 million out of a $1.4 billion total spacecraft development budget.$400M for the TIV, so 1/5 of the spacecraft cost.You don't just look at spacecraft cost, you look at mission cost. This properly accounts for shorter missions on SLS vs Atlas. You don't count the Huygen's probe as an instrument(I assume this is what you mean by "TIV"). It is an instrumented lander. If the 200 million is right, it is 200 million out of 3.3 billion or 6%.
Quote from: ncb1397 on 10/09/2014 05:44 pmQuote from: Jim on 10/09/2014 05:22 pmQuote from: metaphor on 10/09/2014 04:55 pmAccording to this source(pdf), Cassini's scientific instrument cost was $200 million out of a $1.4 billion total spacecraft development budget.$400M for the TIV, so 1/5 of the spacecraft cost.You don't just look at spacecraft cost, you look at mission cost. This properly accounts for shorter missions on SLS vs Atlas. You don't count the Huygen's probe as an instrument(I assume this is what you mean by "TIV"). It is an instrumented lander. If the 200 million is right, it is 200 million out of 3.3 billion or 6%.TIV is Titan IV. $1.4B total mission cost - $400M LV = $1B spacecraft. Instruments are 1/5 of it.
The total cost of this scientific exploration mission is about US$3.26 billion, including $1.4 billion for pre-launch development, $704 million for mission operations, $54 million for tracking and $422 million for the launch vehicle. The United States contributed $2.6 billion (80%), the ESA $500 million (15%), and the ASI $160 million (5%).
Your 1.4 Billion is only "pre-launch development".
Quote from: ncb1397 on 10/09/2014 06:13 pmYour 1.4 Billion is only "pre-launch development".So 1/7 of the spacecraft, which is still a sizable portion.
Now calculating the "portion" to be the percentage of the spacecraft vs the percentage of the mission is moving the goal post.
You don't just look at spacecraft cost, you look at mission cost. This properly accounts for shorter missions on SLS vs Atlas. You don't count the Huygen's probe as an instrument(I assume this is what you mean by "TIV"). It is an instrumented lander.
$422M in 1997 for Cassini TitanIV-Centaur launch vehicle. $625M today with inflation factored in. How much more expensive for SLS, add another $375M =$1B? AtlasV 541 $226M, good price but availability?
Another update for Europa: Cubesat proposals!http://www.astrowatch.net/2014/10/jet-propulsion-laboratory-selects.htmlIf they can get those things into Europa orbit, they could be a boost for gravity and magnetic mapping, but aside from what instruments could get crammed in, the question I ponder is how they'd be placed in orbit while, presumably, the long-lived mothership (Europa Clipper or otherwise) continues circling Jupiter.
This stuff is tossed around as an idea, but I have real doubts about its practicality. Small spacecraft don't have any shielding. How long are they going to last in that radiation hell? And is that the best use of that limited mass?
I wonder how a Falcon Heavy compares; if SLS is "too fantastic" and the Atlas too underpowered for a direct flight, could an FH deliver something to Jupiter with a single Earth fly-by?
I'm guessing with the cubesats they're just exploring all the options right now. There's only so much you can spend $100 million dollars on for "studies".Quote from: redliox on 10/09/2014 08:31 pmI wonder how a Falcon Heavy compares; if SLS is "too fantastic" and the Atlas too underpowered for a direct flight, could an FH deliver something to Jupiter with a single Earth fly-by? The FH might be able to get about 6 tons to a 2-year solar orbit so the spacecraft could do an Earth flyby to Jupiter, like Juno. But in that case you would need more fuel on the spacecraft itself for the needed deep-space maneuver of about 600 m/s delta-v. Also, it wouldn't save much time compared to a VVE/VEE gravity assist transfer (about 5 years instead of 6).
Yeah, that is how they would have to be used--short life. But that itself is an issue. If you are a mission designer and somebody says "I want 10 kg of payload to operate some cubesats for about 1 hour of data and there is high risk that they will fail immediately," will you sit there and say "Go on..." or will you kick that person out of your office? Put more diplomatically, are short-lived cubesats the proper way to spend mass? Is it a good idea to spend many years to send an instrument to Europa that is only going to last a very short time?I have a friend who is currently a PI for a NASA-led planetary cubesat mission and they have noted that many of the things that keep cubesat costs down--short lives, high risk, limited testing--are things that you don't want on an expensive planetary mission.So if you're going to use them, they better be really really worth it. Otherwise, that mass could probably be put to better use as shielding.