New Mars Forums

Official discussion forum of The Mars Society and MarsNews.com

You are not logged in.

Announcement

Announcement: As a reader of NewMars forum, we have opportunities for you to assist with technical discussions in several initiatives underway. NewMars needs volunteers with appropriate education, skills, talent, motivation and generosity of spirit as a highly valued member. Write to newmarsmember * gmail.com to tell us about your ability's to help contribute to NewMars and become a registered member.

#126 2021-09-17 20:07:51

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 23,908

Re: Scouting Mars by Helicopter

I think the issue is the wireless communications can not get a good link back to the rover for further commands accurately for the rovers reciever transmitter antenna system..

No dates are given for the scaling of design work for heavier and larger helicopters but I hope they are sooner not later.
https://rotorcraft.arc.nasa.gov/Publica … _final.pdf
An Advanced Mars Helicopter Design

Offline

#127 2021-09-17 20:24:17

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 8,096

Re: Scouting Mars by Helicopter

For SpaceNut re #126

The report indicated that the density of the air on Mars is changing.  This is (according to the article) not unexpected.

Ingenuity was not expected to last this long.    It has almost no air to work with in the first place, and now it has less.

Radio communication is not a factor in the situation. 

I tried to include the crucial information in the quote, because I know that forum members do not have time to visit every link that gets posted. 

In this case, since my quote somehow caused you to think radio communication had something to do with the problem, it would appear necessary to take the time to read the original article.

(th)

Online

#128 2021-09-17 20:31:20

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 23,908

Re: Scouting Mars by Helicopter

Density changes with altitude as they are going up the hill...it also changes from night to day and from summer to winter...

I am also wondering if mars dust is also playing into this as the build up on the surfaces would add mass for its current flights that its making causing it to need more energy for lift and if the rotors are also getting dust into the sleeve bearings then the tip speeds are also slowing...

edit
I double check the weather topic to see what the barometer was doing and its going down
here is the comparison of the rover sights
24729_PIA23518-Mars-landing-sites-web.jpg

So is the atmospher shape to depth shifting as we go from winter to summer or vis versa...as there is a shift of 35 to 50 kpa in pressure since the periods of the comparisons were made in the weather topic.

Offline

#129 2021-09-18 09:50:59

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 23,908

Re: Scouting Mars by Helicopter

https://mars.nasa.gov/technology/helico … nd-harder/

When we designed and tested Ingenuity on Earth, we expected Ingenuity’s five-flight mission to be completed within the first few months after Perseverance’s landing in February 2021. We therefore prepared for flights at atmospheric densities between 0.0145 and 0.0185 kg/m3, which is equivalent to 1.2-1.5% of Earth’s atmospheric density at sea level. With Ingenuity in its sixth month of operation, however, we have entered a season where the densities in Jezero Crater are dropping to even lower levels. In the coming months we may see densities as low as 0.012 kg/m3 (1.0% of Earth’s density) during the afternoon hours that are preferable for flight.

The difference may seem small, but it has a significant impact on Ingenuity’s ability to fly. At our lower design limit for atmospheric density (0.0145 kg/m3), we know that Ingenuity has a thrust margin of at least 30%. Thrust margin refers to the excess thrust that Ingenuity can produce above and beyond what is required to hover. That additional thrust is needed on takeoffs and climbs, during maneuvers, and also when tracking terrain with varying height. But if the atmospheric density were to drop to 0.012 kg/m3 in the coming months, our helicopter’s thrust margin could drop to as low as 8%, which means that Ingenuity would be operating close to aerodynamic stall (a condition where further increases in the blade’s angle of attack does not produce more lift, only more drag).

We will begin by performing a high-speed spin of the rotor without leaving the ground, reaching a peak rotor speed of 2,800 rpm (more than a 10% increase relative to our prior Mars experience of 2,537 rpm). If all goes well, we will follow this with a short test flight at a slightly lower rotor speed of 2,700 rpm.
A rotor speed of 2,800 rpm, in combination with wind and helicopter motion, could cause the tips of the rotor blades to encounter the air at nearly 0.8 Mach – that is, 80% of the speed of sound on Mars.

Flight elevaional change from starting on mars elevation to the last flight has gone up
PIA24690-web.jpg

Offline

#130 2021-09-18 10:21:34

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 8,096

Re: Scouting Mars by Helicopter

For SpaceNut re helicopter ...

In a light hearted moment of enthusiasm, you recently suggested a helicopter might be a useful addition to the Landing Site engineering probe design. 

The lander (per Drafts 1-6 by GW Johnson) is NOT designed to carry out ANY exploration of ANY kind beyond the two dedicated mission objectives:

1) drill 10 meters down for water
2) Pound the soil for many meters all around the lander, to characterize the regolith for a future lander

A helicopter would  consume mass and (as far as I can see) contribute nothing to the success of the primary mission.

However, you may well see a value to having a helicopter on the scene that I've missed, so here is your chance to elaborate on why such a vehicle should be included.

(th)

Online

#131 2021-09-18 10:25:54

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 23,908

Re: Scouting Mars by Helicopter

Speed to map a safe course travel lane for the rover that needs to get to a site to drill since we are making the rover to be tiny and unless they carry solar panels to keep powered up the distance from the lander for recharge makes for a slow limited path by the rovers cameras being used to pick a course as the current rovers do now is very slow.

Offline

#132 2021-09-18 19:05:48

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 8,096

Re: Scouting Mars by Helicopter

For SpaceNut .... re #131

The rover is a pounder, not a drill.

The drill is fixed in position and does not need the helicopter.

The rover is a ground vehicle that moves in 1 meter steps to pound the soil, take observations, retrieve the pounder and move again.

There is no need for a helicopter for a landing pad engineering mission.

Edit: On second thought ... perhaps a helicopter ** would ** make sense, if it can be fitted into the mass allocation that GW Johnson appears to have in mind.

It occurred to me that a helicopter could scan the entire area of the landing pad quite rapidly, whereas the rover is going to move very slowly, a meter at a time, in order to visit every square meter of the landing pad at a given site.  Perhaps the helicopter could save the rover-pounder time by identifying rocks that are going to prevent a landing at that site.

The drill needs to complete it's work even if the landing site has to be scrubbed, because if there is water present, then another landing site can be used, and an overland expedition can visit the scrubbed site.

OK ... it's up to GW Johnson now to decide if he wants to try to add the complexity of a helicopter to what was intended to be a very simple mission to obtain just two kinds of data.

(th)

Online

#133 2021-09-29 20:03:06

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 23,908

Re: Scouting Mars by Helicopter

The testing of the higher level of rpm for sustained flight has caused it to give an error so no flight for now until they figure it out.

NASA aborts flight Mars helicopter flight after 'anomaly' detected

AAOXKI9.img?h=480&w=799&m=6&q=60&o=f&l=f

This flight would have shown Ingenuity's ability to fly with 2,700 revolutions per minute, slightly more than the 2,537 rpms it has used previously

higher rpm require for the new lift value due to lessening air pressure.

INGENUITY FLIGHTS SO FAR
Flight one: April 19, 2021 with a vertical takeoff up to 9.8ft, stationary hover and a landing

Flight two: April 22, 2021 with a vertical takeoff up to 16ft, hover, then shift westward for 14ft before returning and landing

Flight three: April 25, 2021 with a vertical takeoff up to 16ft, hover, shift northwards for 328ft at an airspeed of 2 m/s before returning to land

Flight four: April 30, 2021 with a vertical takeoff up to 16ft, hover, shift southwards 873ft at 3.5m/s before returning to land

Flight five: May 7, 2021 with a vertical takeoff up to 33ft, hover, shift southwards 423ft at 3.5 m/s before landing at that new location

Flight six: May 22, 2021 with a vertical takeoff of 33ft, hover, shift southwest 492ft at 9mph, travel 49ft south, travel 164ft before returning to land

Flight seven: June 8, 2021 with a vertical takeoff of 33ft, hover, shift 348ft at 9mph, land at Airfield D

Flight eight: June 21, 2021 with a vertical takeoff, hover, shift southwest 520ft, land at Airfield E 438ft away from Perseverance

Flight nine: July 5, 2021 with a record length of 2,050ft southwest over a prospective research location at 16ft per second.

Flight 10: July 24, 2021 with a record height of 40 feet (12 meters) over Raised Ridges to Airfield G. Flight duration 165.4 seconds.   

Flight 11: August 5, 2021 by flying 1,250ft for 130 seconds in preparation for a series of reconnaissance missions for the Perseverance rover.

Flight 12: August 16, 2021 by flying 1,476ft for 169 seconds, climbing 32.8ft in the air, over the 'South Seitah' region of Mars.

Flight 13: September 5, 2021 by flying 690ft for 160.5 seconds, climbing 26ft over one particular ridgeline over the 'South Seitah' region of Mars.

Offline

#134 2021-10-25 19:43:39

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 23,908

Re: Scouting Mars by Helicopter

Time to get ready Mars helicopter Ingenuity approaches 14th flight

The Mars helicopter Ingenuity is ready for a short Martian flight as early as Saturday to test summer weather conditions that have arrived at its location on the Red Planet after two weeks of no communication because of blockage by the sun.

As the heat of summer grows the mars air is going to get thinner and will require even higher rpm's for the blades to create sufficient lift.

What is the lift formula or equation?

The lift formula or equation is CL ½ p V2 S.
CL is the coefficient of lift.  In general, this is the angle of attack on the rotor blade.  Until the stalling angle is reached, an increase in the CL will produce more lift.

½ p V2 This section of the formula is Dynamic Energy or Kinetic Energy.  Basically, dynamic/kinetic energy is derived from the movement of air.  The p is for pressure or air density.*  The greater the density (lower pressure altitude) the more lift produced.

V2 is for velocity or the rotor RPM with regards to helicopter flight.  As referenced by the squared component, velocity is a major factor in lift production.

CL=ρv2A2L

Offline

#135 2021-11-09 20:06:35

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 23,908

Re: Scouting Mars by Helicopter

The 15th flight  has happened and its returned basically back to near its starting point to support the rovers new direction of travel.

https://www.space.com/mars-helicopter-i … 5th-flight

https://mars.nasa.gov/technology/helico … n-journey/

The team lead Teddy Tzanetos of JPL laid out the flight plan in that post, stating that Ingenuity would cover 1,332 feet (406 meters) of horizontal distance, travel at 11.1 mph (17.9 kph) and fly about 39 feet (12 m) above the ground. The recent flight was also the second in which Ingenuity spun its rotors at 2,700 revolutions per minute  (RPM), compared to about 2,500 RPM on the first 13 flights. The increase was necessitated by a seasonal shift on Jezero's floor; it's summer there now, and the air is less dense

Offline

#136 2021-11-23 18:23:46

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 23,908

Re: Scouting Mars by Helicopter

Mars helicopter Ingenuity completed its 16th flight over the weekend, the space agency announced Monday.

wow 7 months on Mars

The NASA Jet Propulsion Laboratory said the helicopter captured color images of Mars' surface during the flight, which saw it travel 116 meters northeast for 109 seconds.

Now can we make it for human size?

Offline

Board footer

Powered by FluxBB