SAAB JAS 39A/B/C/D Gripen

Apparently, the third batch of Gripens (Gripen C/D) were produced with a redesigned radar section that featured enlarged radar back-end LRU bays, reflecting the NORA studies. Should be one of the reasons why Sweden scrapped so many Gripens by 2014 (should be more by now). Though this makes me wonder if the 66 Gripen As converted into C model also features a modified radar LRU compartment.
 
Hungary has bought four more Gripen C taking its 20 year old fleet from 14 to 18 (its existing 14 are on hire-purchase and that contract was also extended until 2035).

Hungary to get more Gripens from Saab | Shephard

The new order followed a 2022 announcement that Saab would modernise the Hungarian Air Force’s current fleet of 14 JAS 39C/D Gripen fighter aircraft.
www.shephardmedia.com
 
GTX said:
breakingdefense.com

Sweden commissions study on Gripen fighter jet satellite launch capability - Breaking Defense

As adventurous as the Swedish study sounds, there is no guarantee that it leads to a future operational capability.
breakingdefense.com breakingdefense.com
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Bet me to posting this ! From the Boramae engine post and the link there, to Breakingdefense.com. Studies like that have existed since Project NOTS / CALEB, vintage 1958 in the wake of Sputnik. Or perhaps even before.
A Mach 2 fighter jet can scrap 1600 m/s out of an ascent to orbit 9000 m/s. Not negligible, except what matters is the raw energy rather than the delta-v: and bad luck, there is an exponential nested in the equation. So energy wise it is not much, plus the Gripen has a limited bombload, translating into a very limited rocket weight, plus hydrolox is a giant PITA but anything else has much less specific impulse... end result of the whole train wreck: perhaps 100 kg to orbit. Then again: cubesats. Albeit they existed since 25 years and air-launch is still stuck in limbo. The 800 pound gorilla is SpaceX F9 Rideshare, which is presently making a massacre of all the small rocket startups. Even Rocketlab's Beck is freaking out.
A decade ago or two, Dassault had similar plans for the Rafale. So had the Israelis from their F-15s. Or was it ALASA ? same plane, but DARPA, and it went nowhere. Also the russians from their MiG-31s.

We shall see...
 
The Russians have everything in perfect order with their MiG-31. The mass of the satellite is more than 100 kilograms

1538298941_d9yiry9oj8y.jpg
 
Archibald said:
Bet me to posting this ! From the Boramae engine post and the link there, to Breakingdefense.com. Studies like that have existed since Project NOTS / CALEB, vintage 1958 in the wake of Sputnik. Or perhaps even before.
A Mach 2 fighter jet can scrap 1600 m/s out of an ascent to orbit 9000 m/s. Not negligible, except what matters is the raw energy rather than the delta-v: and bad luck, there is an exponential nested in the equation. So energy wise it is not much, plus the Gripen has a limited bombload, translating into a very limited rocket weight, plus hydrolox is a giant PITA but anything else has much less specific impulse... end result of the whole train wreck: perhaps 100 kg to orbit. Then again: cubesats. Albeit they existed since 25 years and air-launch is still stuck in limbo. The 800 pound gorilla is SpaceX F9 Rideshare, which is presently making a massacre of all the small rocket startups. Even Rocketlab's Beck is freaking out.
A decade ago or two, Dassault had similar plans for the Rafale. So had the Israelis from their F-15s. Or was it ALASA ? same plane, but DARPA, and it went nowhere. Also the russians from their MiG-31s.

We shall see...
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No, a Mach 2 airplane flies at 680 m/s, not 1600.
 
Hobbes said:
No, a Mach 2 airplane flies at 680 m/s, not 1600.
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Also removes a lot of atmospheric drag that gets counted as 9km/s to orbit. Orbital speed is only about 7km/s. The rest is gravitational and atmospheric drag losses.
 
I forgot to add the altitude and angle of attack (30 degrees), which makes 1600 m/s (see attached paper). It is not just the plane velocity.

And yes, you have to consider the ascent losses. Everybody launching in orbit has to bit that bullet.
 

Attachments

  • A.4.2.1 Launch Method Analysis (Air Launch).pdf
    86.3 KB · Views: 3
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Archibald said:
Gripen has a limited bombload, translating into a very limited rocket weight, plus hydrolox is a giant PITA but anything else has much less specific impulse... end result of the whole train wreck: perhaps 100 kg to orbit.
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100kg to orbit would be a major achievement. alot of Ground launched small sat LVs aim for that figure. DARPA ALASA which was supposed to be launched from F-15 was supposed to have a payload of 45kg, and that with a mono propellant design. No way in hell Gripen launches even half that and in fact, it's 2kg payload they are envisioning.

Sweden Exploring Gripen Responsive Space Launch Capability | Aviation Week Network

The Swedish Air Force has begun a study into the possibility of launching a satellite from its Saab Gripen fighter aircraft.
aviationweek.com aviationweek.com
 
Maro.Kyo said:
100kg to orbit would be a major achievement. alot of Ground launched small sat LVs aim for that figure. DARPA ALASA which was supposed to be launched from F-15 was supposed to have a payload of 45kg, and that with a mono propellant design. No way in hell Gripen launches even half that and in fact, it's 2kg payload they are envisioning.

Sweden Exploring Gripen Responsive Space Launch Capability | Aviation Week Network

The Swedish Air Force has begun a study into the possibility of launching a satellite from its Saab Gripen fighter aircraft.
aviationweek.com aviationweek.com
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What on earth are they using a 2kg satellite for? recon?
 
100kg to orbit would be a major achievement. alot of Ground launched small sat LVs aim for that figure. DARPA ALASA which was supposed to be launched from F-15 was supposed to have a payload of 45kg, and that with a mono propellant design. No way in hell Gripen launches even half that and in fact, it's 2kg payload they are envisioning.
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There are many different rocket parameters, notably the number of stages, the props, countless others. Payload varies accordingly.

en.wikipedia.org

Aldebaran (rocket) - Wikipedia

en.wikipedia.org en.wikipedia.org

Did knew about that study, damn interesting stuff.
 
But why a Gripen? Isn´t there any AJ37 left that can be restored for that purpose (and reengined with something that push harder)?

Better MTOW, better lift (wing area >> by 50%). More sturdy Landing gear easier to strengthen with larger tires), taller also for larger carried rocket, Deeper volume to add fuel, older avionics, bulkier, that when deleted will increase the available volume for tanks and ancillary equipment etc...

One or two regenerated Viggen would certainly not bankrupt the SwAF.
 
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Scott Kenny said:
What on earth are they using a 2kg satellite for? recon?
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Can be used in swarms for imaging or communication, there were 396 Nano-sat (1-10kg) launched last year and they've averaged around 300 a year for the last five years. Generally used for cheap always on imaging or when you need to temporarily surge communication bandwidth in a particular location. Also good as a platform for microgravity experiments by universities as you launch them for $10k-100k which brings them within many departmental science budgets.
 
WatcherZero said:
Can be used in swarms for imaging or communication, there were 396 Nano-sat (1-10kg) launched last year and they've averaged around 300 a year for the last five years. Generally used for cheap always on imaging or when you need to temporarily surge communication bandwidth in a particular location. Also good as a platform for microgravity experiments by universities as you launch them for $10k-100k which brings them within many departmental science budgets.
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Right. In swarms.

This is launching ONE ~2kg satellite per Gripen.
 
You launch a constellation shell of six, but one satellite fails... you have a 4 hour gap in coverage each day.

Its a rapid response launch capability to plug the gap which can be done with only hours notice, which would otherwise wait months if not years to piggyback on another launch going to a similar orbital trajectory (as orbital insertion would be beyond their onboard engine capabilities), these microsats only usually have a life of a couple of years so odds are you wont be able to repair the constellation before it decays.

Or if there's an urgent need to recon a particular location for example after a natural disaster or a military crisis.

Its similar to the US Space Command TacRS program which commissioned amongst others Rocket Lab for Victus Haze (An orbital tug built on a 120kg sat bus), this followed the test with an Firefly Alpha rocket to launch Victus Nox with only 27 hours notice (Firefly alpha has capability to launch upto six cubesats to low earth or polar orbits) and USSC previously developed the 6U Monolith satellite (a 6U sat has a max limit of 12kg) as a platform for rapid response surveillance. A 2kg sat would be a 1U or 2U cubesat.

If you dont think 1U or 2U is a meaningful size, look at a list of just some of the cubesats
en.wikipedia.org

List of CubeSats - Wikipedia

en.wikipedia.org en.wikipedia.org
 
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From link above (and for reading simplicity):

There are many types of CubeSats ranging from 0.25u to 16u.[43] In the Type column, the number corresponds to the (approximate) length of the CubeSat in decimetres. Width and depth are normally ten centimetres, or one decimetre. A 1U CubeSat measures approximately 1 × 1 × 1 decimetres, while a 6U CubeSat is six times the size, approximately 1 × 2 × 3 decimetres.[44]
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To complete also my post above on the merits of using an AJ37 instead of the smaller Gripen, let´s also remember that both Swedish fighters have fixed inlets, lengthening the time needed to accelerate to the launch speed. IMOHO, it would be easier to start with Viggen as, it has bigger inlets to work with for any engine upgrade.
Also Viggen ceiling and max Mach are superiors.
 
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TomcatViP said:
IMOHO, it would be easier to start with Viggen as, it has bigger inlets to work with for any engine upgrade.
Also Viggen ceiling and max Mach are superiors.
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Except that the Viggen has been retired for over 17yrs...
 
GTX said:
Except that the Viggen has been retired for over 17yrs...
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Rather a shame just because I think it was a rather unique fighter. I don't know if Sweden would have been open to such a deal, but I think it would have been great if one of those companies that does aggressor training had bought a few of then-retired aircraft.
Many lavish the Gripen with endless praise but to me the Gripen seems to mostly be an updated take on the easy-to-operate lightweight fighter, the best comparison probably being with the Northrop F-20 which simply was at the wrong time to see any export success. The Viggen in comparison just seems like it was a lot more ambitious for its time.
 
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Colonial-Marine said:
Rather a shame just because I think it was a rather unique fighter. I don't know if Sweden would have been open to such a deal, but I think it would have been great if one of those companies that does aggressor training had bought a few of then-retired aircraft.
Many lavish the Gripen with endless praise but to me the Gripen seems to mostly be an updated take on the easy-to-operate lightweight fighter, the best comparison probably being with the Northrop F-20 which simply was at the wrong time to see any export success. The Viggen in comparison just seems like it was a lot more ambitious for its time.
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I'd say that making a unique fighter (in this case, a fully competitive light fighter) was a far more ambitious goal.
 
Ainen said:
I'd say that making a unique fighter (in this case, a fully competitive light fighter) was a far more ambitious goal.
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I'm still not entirely convinced that the Gripen is a fully competitive light fighter. Pretty sure it's only seen 1 major export sale, everything else has been countries leasing used Gripens that SwAF has replaced in their own ORBAT.

Bluntly, I think it's just too small physically to have much growth room.
 
It´s not small. The E is comparable to a Mirage 2K and compete on the same market (albeit now regrettably completely deserted by Dassault).
 
TomcatViP said:
It´s not small. The E is comparable to a Mirage 2K and compete on the same market (albeit now regrettably completely deserted by Dassault).
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And the E is bigger than the earlier versions.

The OG Gripen A-D ran out of fuselage volume to upgrade the electronics. It is 5 tonnes lighter than an F16C-50/52 at MTOW, 1700kg lighter than that same F16 empty. Gripen E/F is 500kg lighter than our F16C-50/52 empty, 2500kg lighter at MTOW.
 
Scott Kenny said:
And the E is bigger than the earlier versions.

The OG Gripen A-D ran out of fuselage volume to upgrade the electronics. It is 5 tonnes lighter than an F16C-50/52 at MTOW, 1700kg lighter than that same F16 empty. Gripen E/F is 500kg lighter than our F16C-50/52 empty, 2500kg lighter at MTOW.
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It(C/D fleet) is still getting a comprehensive electronics update right now(2023-29). Electronics aren't getting bigger with time, and not like vanilla gripens lacked any specific capabilities of a modern MRF.

Gripen E, from what I understand, is mostly an export-driven change (range, especially supersonic; desire to get into delicious mirage 2000 niche).

Sweden itself didn't really need a heavier airframe that much. With NATO commitments it'll be handier, though.
 
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