0

Simple question really - would ICBMs be visible to a person from the ground on a clear night, in much the same way the Starlink satellites have been? Edit - to be clear, I'm meaning when the warheads are in flight, pre re-entry.

I know there's a size difference, but I can't see why not if you can see a satellite.

Organic Marble
  • 181,413
  • 9
  • 626
  • 815
NDJ
  • 109
  • 4
  • 3
    Do you mean the rockets themselves on launch, or the warheads? The warheads separate from the booster and then re-enter separately. – GdD Jun 04 '20 at 16:27
  • I meant the warheads - pre re-entry. – NDJ Jun 04 '20 at 16:39
  • 1
    It would make sense to edit your question with these details @NDJ. I'm not surprised there's no data because 1) there's never been a nuclear war, so few spotting opportunities, 2) governments are very tight lipped about the observability of their weapons, you wouldn't want the enemy to know how to spot your MIRVs. – GdD Jun 04 '20 at 16:41
  • The MIRVs are quite small and black with no faceted surfaces. It seems unlikely. https://en.wikipedia.org/wiki/Multiple_independently_targetable_reentry_vehicle Reentry- completely different https://en.wikipedia.org/wiki/File:Peacekeeper-missile-testing.jpg Not sure if this is on topic either. – Organic Marble Jun 04 '20 at 17:15
  • If you rely on reflection it highly depends on the sun angle. – user3528438 Jun 04 '20 at 17:21
  • It would be quite hard to answer this question; one rarely will be able to see an MIRV flying, as if that was so, then warhead engineers probably did everything wrong in designing it. Probably not. – WarpPrime Jun 04 '20 at 18:01
  • It would not be hard to write a reasonable answer to this question if you can mention at least a rough estimate the size, shape and reflectivity of a warhead. A 50 cm sphere with a reflectivity of 0.1 would almost certainly be hard to see even if sunlit while night on the ground (and that would be a rare situation itself, not to mention nuclear war being rare) whereas a 10 meter long rocket body with a reflectivity of 0.9 would be easily visible, if sunlit while night on the ground. – uhoh Jun 05 '20 at 00:17

3 Answers3

3

Answer: Maybe

Visibility = area x albedo / altitude

MIRVs are about 2 meters long, about the same size as a Starlink satellite bus. Starlink solar panels are significantly larger than 2 meters, but they contribute little to the satellite’s visibility.

However, MIRVs peak altitude is 900miles. This is considerably higher than Starlink at 342 miles (they are lower as a freshly launched “necklace”). https://history.nasa.gov/SP-4201/ch3-3.htm#:~:text=In%20a%20typical%20ICBM%20flight,could%20reach%2012%2C000%20degrees%20F https://ts2.space/en/what-is-the-altitude-at-which-starlink-satellites-orbit/#gsc.tab=0

Starlink satellites are highly reflective whereas published photos of actual MIRVs are invariably black. Published photos of non-black MIRVs are likely dummy warheads.

enter image description here

In the absence of authoritative information, I would assume the black casing on MIRVs is Radar Absorbent Material (RAM) to reduce detection. Even during WWII, when RADAR was new, RAM was available which reduced detection by 26db (10% of non-RAM detection distance). https://apps.dtic.mil/sti/tr/pdf/ADA215068.pdf

However, black coating increases absorption of radiation from Directed Energy Weapons. It also makes ground observation by visible light more difficult.

Directed energy weapons (DEW) in the Strategic Defence Initiative (SDI) included chemical lasers. They had “limited success” as shown by an airborne laser which successfully intercepted a missile at launch. https://en.wikipedia.org/wiki/Strategic_Defense_Initiative

One proposed countermeasure to DEW was high albedo coating on MIRVs to reflect incoming laser radiation. High reflectivity mirrors had been developed for orbiting relay mirrors (to reflect ground-based lasers), as in the Relay Mirror Experiment (RME) , part of the SDI. It has been proposed these mirror coatings be applied to MIRVs to defend against DEWs.

I don’t have authoritative information on albedo for currently deployed MIRVs

Bottom line: MIRVs could be as naked-eye visible as Starlink satellites if

  • They weren’t black.

  • Their flight path was not in the earth’s umbra'

  • They were in the ascending (or descending) portion of their ballistic course.

Woody
  • 21,532
  • 56
  • 146
  • 1
    Another if is that the observer would need to be in a dark sky location, on a clear night, a place where you can see fainter satellites, the Milky Way, faint shooting stars, etc. And if the warhead was launched at an optimal dusk or dawn time for that location. And passed over high enough in the sky to see. However even with all of that in place almost no one would notice it, most people don't even notice ISS when it passes over. Even if someone was looking for it (perhaps hearing about incoming missiles) they wouldn't be able to identify it, other than by not finding it in their tracking app – Steve Pemberton Dec 17 '23 at 02:04
  • @StevePemberton ... Yes. Eyeballs make a lousy early warning system. – Woody Dec 17 '23 at 02:36
  • @Woody Depends on where they are. Eyeballs near the launch site would probably have the earliest warning ;) – Dragongeek Dec 17 '23 at 22:11
  • +1 - this might be quite interesting for anyone who is a part of an organisation planning a test launch. I was also wondering if the question was for a novel. Also, the range obviously changes dramatically between the 1500km peak altitude and the start of the glowing part of re-entry so perhaps, for a small camera rather than the naked eye, a reflectivity of 10% ( i.e. 136 W/m^2 if all other conditions are right) might be enough to see where it is going. – Puffin Dec 19 '23 at 00:46
  • The flight alittiude is 1000 and the umbra is 12000km so they would be visible for just at dawn/dusk if they were painted white. Because of satellites, they are not painted white very much i.e. russian ones are dark green. During re-entry they burn very hot so that would be visible. – bandybabboon Dec 23 '23 at 11:29
  • @bandybabboon - "During re-entry they burn very hot so that would be visible". In the question it stated "to be clear, I'm meaning when the warheads are in flight, pre re-entry." – Steve Pemberton Dec 23 '23 at 15:24
-1

Here is a photo of 8 dummy MIRVs from a single “Peacekeeper” ICBM landing on an unsuspecting Kwajalein Atoll. Each real MIRV warhead is about 20 times the kilotons of the Hiroshima bomb. Think about the world we live in and the thread we live under. Someone in marketing came up with the "Peacekeeper" name.

ICBMs would certainly be visible in the launch and re-entry phases.

enter image description here A Peacekeeper missile deploys eight warheads during a re-entry test on Kwajalein Atoll in the Marshall Islands. (David James Paquin / Wikimedia)

Woody
  • 21,532
  • 56
  • 146
  • I posted that in a comment to the question back in 2020. The question clearly says pre-reentry. – Organic Marble Dec 19 '23 at 01:41
  • 1
    @OrganicMarble ... sadly, there is an unescapable connection between the industry which creates ICBMs and the industry which enables space exploration. Don't look up, – Woody Dec 19 '23 at 02:02
  • I remember that picture, glad someone has posted it, +1, even though not strictly on topic as during re-entry – Puffin Dec 28 '23 at 12:53
-2

A 10m ICBM at 1000km altitude is like spotting a 1mm object at 100 meters or a pigeon at 50km away.

When it is about to do re-entry, you can reduce that task to spotting a baby mosquito that appears at 8 meters for half a second away and a pigeon at 4km away.

Otherwise, it depends on the time of day if you have a telescope and want the sun to reflect from the ICBM because they are rapidly in the earth's shadow. ICBM's can fly at 2x the altitude of Starlink ( 1000 vs 550 km)so they can stay out of the shadow for longer.

Starlink is 24m2 and visible on the horizon at dawn and dusk. Starlinks are more reflective than ICBM's.

Many ICBM's are painted in dark colors, camouflage, military colors and even black. For most of the journey ICBM's cost at high altitude, outside of the atmosphere, in the shadow of the earth, or invisible at 1000km in the daytime sky. ICBMs switch off their engines during the midcourse, or coasting, phase of their trajectory.

The re-entry phase will be the brightest, due to intense heat from atmospheric friction, a few percent as bright as spaceshuttle on re-entry. a bit like this except it would not slow down as much, staying close to 25000km/h

enter image description here

ICBMs use liquid propellant that produces an efficient blue flame of far lower luminosity than what we think of as a flame, as you can see by the contrast between the oxygen-alcohol fire here and it's reaction with a lower temperature yellow combustion:

curiously the asteroid that killed the dino's could have been visible for weeks if it had a trail of 20-30 miles due to solar reactions. It would have taken 5-8 seconds to go through the atmosphere.

bandybabboon
  • 302
  • 1
  • 9
  • 2
    Do you have a reference for your claim that "ICBMs have a small blue flame"? I'd also be interested in references regarding camouflage painted MIRVs. Do they use "realtree"? – Organic Marble Dec 21 '23 at 17:09
  • Yes I rephrased it to be less of a simple statement and added soem images. – bandybabboon Dec 23 '23 at 11:14
  • @organicmarble, you can websearch to see the colors of icbm's including minuteman, very variable, black, green, yellow, white. I.e. Russia's ones are all dark green, it helps them stay invisible at any time during transport and use. – bandybabboon Dec 23 '23 at 11:26
  • 1
    The question is about the warheads, not the boosters. And it specifically says pre-re-entry. The warheads don't have any flames coming out of them when they are in orbit. Your answer has nothing to do with what the question is about. Please read the question. Also, most ICBMs are solid-fueled. – Organic Marble Dec 23 '23 at 11:53
  • @bandybabboon - "Russia's ones are all dark green, it helps them stay invisible at any time during transport and use." You would think they would paint them black if they were concerned about people spotting them visually while they are coasting in space. Green is likely a choice of color for when the ICBM is on the ground which is when they prefer to avoid visual detection. Once launched the warhead will be quite visible on radar regardless of what color it is painted. – Steve Pemberton Dec 23 '23 at 15:35
  • @StevePemberton They have them on trucks, I meant spotted from space. https://www.google.com/search?sca_esv=593934404&sxsrf=AM9HkKmq3cDsnn0nL1o-deKsm8qRFtrC6w:1703664970316&q=russian+icbms&tbm=isch&source=lnms&sa=X&ved=2ahUKEwilvfzKlq-DAxXuQ6QEHQPLACUQ0pQJegQIChAB&biw=1708&bih=785&dpr=1.5#imgrc=A0OGuNlHJZB4LM – bandybabboon Dec 27 '23 at 08:16
  • @organicmarble (considering they would be like spotting 1mm (a mosquito) at 100 meters or a pigeon at 50 miles away) sorry i didn't realize it was a totally baseless question like " can you spot a private jet flying at 1000km altitude with just your eyes " If the guy knows the extra stratospheric altitude and excludes all possibility of seeing them, why does he ask the question in the first place??? – bandybabboon Dec 27 '23 at 08:23
  • bandybabboon - I agree the colors are probably about seeing the missiles from space, but while the missile is on the ground. Detailed spy satellite photos are made when a satellite passes overhead of a site, and with all the right lighting, and the camera is pointing directly at the specific location. I don't think a satellite is going to be able to visually identify a missile in flight using an optical camera. A missile in flight can be detected by heat signatures and by following the trajectory and speed. – Steve Pemberton Dec 27 '23 at 13:04
  • @StevePemberton If we develop advanced sensors to detect an ICBM, yes they can see it, using zoom and AI to achieve high confidence of the I.D. an infra-red cmos to image thermal photons from the trajectory would struggle to have catch a lot from the background noise, even with long exposure times. I haven't heard of infra-red imaging used at 1000km, even on earth based telescopes. There are thousands of military satellites, some of them must be specialized to spot ICBMs from space where infra-red is easier to see. – bandybabboon Dec 28 '23 at 03:20