On previous article of our New Horizons series, we tried to explain scientific and historical background of New Horizons Mission.
This is the second article of the series: “New Horizons Mission – Its History, Route, Success and Future”.
On this article, we will focus on scientific goals of this Pluto-Kuiper Belt Mission together with the planned timeline for launching and the flybies.
The list of article series is as follows and the links for the next articles will be here once they are published.
- New Horizons Mission – Historical Background
- New Horizons Mission Goals
- New Horizons Spacecraft
- New Horizons Mission From Launching to Pluto Encounter
- New Horizons Pluto Flyby
- New Horizons Ultima Thule Flyby
New Horizons Mission – We Have Waited So Long!
So did the scientists!
It was a great news for many scientists and Pluto fans! New Horizons Mission was ready to initialize and it was time to build up the team.
Before digging in to the detailed plans of the mission, let’s have a quick glance to New Horizons Mission Team and organizational structure of the project.
Building Up New Horizons Team – The Organizational Design
Before building the New Horizons Team, the decision was to assign a Principal Investigator from universities and research centers and organize the mission program via a PI together with other collaborating institutions. PI person selected for the New Horizons Mission was Alan Stern from Southwest Research Institute (SWRI) Space Studies Department. You might remember him from the “Pluto Underground Team”!
List of major partners supporting the mission excluding several co-investigators from different reasearch institutes and universities are as below:
- Johns Hopkins University Applied Physics Laboratory
- Southwest Research Institute
- Stanford University
- Ball Aerospace Corporation
- NASA Goddard Space Flight Center
- NASA Jet Propulsion Laboratory.
We don’t want to fill this article out with the names. That’s why above is only a list of primary institutions. For a complete list of all parties, see following link: New Horizons Mission Press Kit.
We have another list to introduce you.
Below is a list of New Horizons Mission Science Teams and Operation Centers. For more details and names of scientists, see following link from JHUAPL Project page: New Horizons Team.
- Mission Operations Center (MOC)
- Science Operations Center (SOC)
- Control Center
- Engineering Team
- Navigation Team
- Geology & Geophysics Investigation (GGI) Theme Team
- Composition (COMP) Theme Team
- Kuiper Extended Mission Particles & Atmospheres (PATM) Theme Team
- Kuiper Extended Mission Planning Team
- Atmospheres (ATM) Theme Team
- Particles and Plasma (P&P) Theme Team
- Pluto Encounter Planning (PEP)
New Horizons Mission – Operation Control
The Mission Operations Center located in John Hopkins University Applied Physics Laboratory (JHUAPL) was planned to handle and coordinate the flight controls and mission analysis. While the Navigation Team at Kinetx Inc was the dedicated squad for navigational operations, Science Operations Center in Boulder, Colorado were responsible for the scientific controls.
For the communcation link with the spacecraft, seperate stations of NASA‘s Deep Space Network located in California, Madrid and Canberra were going to be used.
Since there were several different stations for the mission operation, a seperate Control Center at NASA‘s Jet Propulsion Laboratory (JPL) in California was assigned for communication purposes between main and sub operation centers.
So the New Horizons Team and the organization were ready. Eventually the universities, research institutes, companies and students with above organizational tree were going to handle everything.
In addition to above, you need one more thing for such a mission: A spacecraft! With proper instruments as well as the tools to launch and remotely control it.
New Horizons Spacecraft and the Instruments Onboard
Since our next article will be dedicated only to the New Horizons Spacecraft and the instruments on it, we will very briefly mention about the spacecraft here.
The spacecraft was equipped with below listed built-in scientific payloads:
- An imaging spectrometer
- A camera capable of imaging infrared and visible wawelengths
- A long-range telescopic camera
- Particle spectrometers
- Dust particle mass-measurement detectors
- Two sets of radio science equipments.
It was decided to perform launching with an Atlas V-551 rocket. Following the launching, an RTG (Radioisotope Thermoelectric Generator) was designed to be the power source for both navigational and scientific operations.
In addition to above, we can count the antennas, star trackers, data processing and storage units and thrusters as major navigational and operational equipments onboard.
Complete spacecraft building operations were carried out at JHUAPL.
New Horizons Mission Goals and Plans
It was planned to launch the spacecraft in between 11 January – 14 February 2006. The reason is, that period was the best choice considering the advantage of alignment between Earth, Jupiter and Pluto.
Although there were several backup dates on above stated period, the best dates within this period were 11 to 27 January 2006. Because integrating with this period would bring the opportunity for the earliest Pluto arrival and flyby possible: On 14 July 2015.
“What damage would it cause to delay the launching for 2 more days after 27 January?” one could ask. It’d mean one year delay on Pluto flyby for a 2 days delayed launch. What’s more, there would be one more year additional delay for 5 undone launching days! But how can few days have yearly influences on arrival times?
There is one important subject for a spacecraft in such a project: Its speed. Best power-efficient and applicable way to speed up your spacecraft on long one-way journeys is to use gravitational help of biggest objects on the route. However, if the arrival time is not that critical, you can still plan a direct visit though!
In New Horizons Project case, the team calculated the launching deadline for being able to use Jupiter’s gravitational assistance as 2 February 2006. If the launching took place in between 3-14 February, the tickets would have to be changed from Jupiter transfer to direct Pluto flight. Furthermore, if the launching was delayed to 13-14 February; the Pluto flyby date would dramatically be shifted to July 2020!
Delaying The Mission Could Jeopardize Some Parts of Planned Researches
Is it a problem to have years of delays for a $700 Million-mission?
Apart from budgetary reasons, actually there were two more issues with delays:
Pluto was moving off from Sun during those years and big delays could cause incapability of Pluto’s atmospheric analysis since the scarce atmosphere of Pluto was estimated to be slowly condensing. This could cause no atmosphere in hand to explore during flyby! Scientific analysis of the atmosphere was one of the two irrevocable tasks of this mission and risking to call it off would not be very pleasant.
Second issue was the calculated best period for imaging surface features considering the positioning of Pluto and Charon against Sun. The best chance would be caught with the earliest visit and the detailed mapping of both planetary surfaces was the next essential task of this mission.
Daily Launching Periods
While the launching dates and deadlines were limited, daily launching periods were also limited up to maximum of 2 hours. What’s more, daily launching periods were seperately calculated for the best hours on that specific day in terms of launching platform location and Earth-spacecraft trajectory alignment.
New Horizons Mission Goals and Plans: From Launching to Pluto Encounter
Launching was planned to be done via an Atlas V-551 rocket from Cape Canaveral Air Force Station in Florida with a speed of 58.000 kilometers/hour, which could be the fastest launching record in practice.
The timing of launch was broadly effecting arrival times, but in any case the plan was to arrange spacecraft’s seperation and to initialize signal flow from spacecraft to bases on Earth within 1 hour.
If the launching deadline 2 February 2006 was not skipped, New Horizons Spacecraft was planned to perform the closest approach to Jupiter around February-March 2007; than to speed up on its route to Pluto. During the 13 months-journey between Earth and Jupiter, final calibrations and preparations for the scientific researches were to be performed. Hence the New Horizons Team could have the opportunity to test those calibrations with an “on-the-road” Jupiter System glance.
After days of Jupiter was over, it was planned to take the spacecraft to a 7.4 years of “stand-by mode“. During the stand-by years, no scientific researches were going to be carried out. Only an “I’m OK” signal was going to be generated and sent to Earth on daily basis. In the meanwhile, yearly checks & calibrations of spacecraft equipments together with trajectorial corrections would be performed.
5 months before the closest Pluto flyby, the spacecraft was planned to be gently waken up and started sending high resolution Pluto-Charon images to Earth.
As the spacecraft came closer and closer weeks before the encounter, the images from Pluto and Charon was going to become more clear. Those images were going to be inspected and focus-areas with more interesting surface features were going to be decided. Those areas were going to be targeted for more detailed imaging like hundreds of meters of resolution during the closest approaches.
New Horizons Mission Goals and Plans: Pluto Encounter To Do List
If the success for the earliest Pluto-Charon flyby date was achieved, the spacecraft was supposed to perform the closest approach to both icy rocks on 14 July 2015: About 10.000 kilometers away from Pluto and 27.000 kilometers away from moon Charon. During those historical moments, speed of the spacecraft was estimated to be 50.372 kilometers per hour, which was another record for a spacecraft in 2005.
Regarding the data transmission speed from spacecraft to Earth: For the initial high resolution and best images of Pluto and Charon, it was calculated to take minimum 4 hours and 25 minutes for receiving spectral data from spacecraft where the distance between Pluto and Earth was going to be more than 4.92 billion kilometers.
The busiest day of initial 9.3 years of the mission was going to be the closest Pluto flyby moments ± 12 hours. During this period, the tools on spacecraft was going to be on full duty.
During the closest flyby, best images of Pluto and Pluto moons were planned to be acquired. Those images and spectral data would hold the key result about the entire mission: Pioneer information about Pluto System‘s atmosphere, geology, more certain information about sizes and visual details.
New Horizons Mission Goals and Plans: After The Pluto Encounter
The closest encounter was going to reveal many Pluto facts. Next and a crucial operation was after passing by Pluto: It was planned to send out powerful radio signals from Earth, strike them in towards Pluto’s atmosphere and send them to New Horizons Spacecraft. This would yield an invaluable and extremely advanced data of atmospheric composition, temperature and density via analysing the refracted signals.
Than the spacecraft was supposed to continue its route to Kuiper Belt. Sending the complete “prioritized data package” of Pluto System from spacecraft to Earth would take another 9 months during this journey since the downlink speed from that distance was estimated to be about 600-1200 bits per second.
Two weeks after saluting Pluto, the thrusters was planned to be started once more for heading towards the decided next target of New Horizons Spacecraft. That was planned to be chosen from one of the suitable Kuiper Belt Objects with a minimum 50 kilometers diameter. Considering the acceleration in Kuiper Belt Object discoveries, the decision was going to be made right before Pluto encounter days.
It is fun to just imagine the “authorized people” grabbing a Kuiper Belt Object Catalogue and pick one with their fingers!
According to the mission status and possible other Kuiper Belt Objects nearby the trajectory, the mission was planned to be extended for one more object (after next 5-7 years) or to be ended in idle mode and the spacecraft was going to glide towards interstellar space. NASA was the authority to approve such extensive missions through Kuiper Belt.
New Horizons Mission Objectives
For summarizing key points, let’s make a list of scientific objectives of New Horizons Mission:
- Mapping of Pluto surface and Charon surface (See our seperate articles for details of those maps: Pluto Map and Charon Map) with a 1 kilometer resolution in average. In accordance with that, determination of surface composition and identification of surface features.
- Analyzing Pluto Atmosphere: Its composition, formation and escape rate.
- Measuring and mapping surface temperatures.
- Detailed & more enhanced imaging of interesting surface features with a higher resolution than 1kilometer.
- Investigating the variances on Pluto’s surface and atmosphere.
- Imaging Pluto’s dark hemisphere (far side of Pluto).
- Receiving the radio signal from Earth for detailed analysis of Pluto atmosphere.
- Analysis of Pluto’s ionosphere and its interactions with solar wind.
- Imaging terminators of Pluto and Charon in details.
- Searching for an atmosphere around Charon.
- Measurement for bolometric bold albedos of Pluto and Charon.
Minor (But Desirable) Objectives
- Analysis of dust particles in Pluto System area.
- Sensitive measurements of diameter and mass of Pluto and moons.
- Looking for Pluto rings.
- Looking for additional Pluto moons.
- Before the launching, scientists did not know that Pluto had moons other than Charon. Since 4 pcs additional moons (Hydra, Nix, Kerberos, Styx) were discovered from 2005 and 2012; imaging and analysis of those moons were naturally added to the mission plans.
So above is a brief summary of New Horizons Mission Goals before launching.
Obviously there is a third article before the fourth! Click on following link for technical details of operational and scientific instruments on New Horizons Spaecraft.
12-2005, “New Horizons Press Kit“
Link: ( https://www.nasa.gov/pdf/139889main_PressKit12_05.pdf )
- John Hopkins University Applied Physics Laboratory (JHUAPL) Web Page
Details of Mission Team
Link: ( http://pluto.jhuapl.edu/Mission/The-Team.php )
Link: ( http://pluto.jhuapl.edu/Galleries/Graphics.php )
- 09-2007, “The New Horizons Pluto Kuiper belt Mission: An Overview with Historical Context“
Link: ( https://arxiv.org/ftp/arxiv/papers/0709/0709.4417.pdf )
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