Space stocks are having a moment, and two names leading the discussion today are Rocket Lab Corporation (RKLB Quick QuoteRKLB - Free Report) and SpaceX (SPCX Quick QuoteSPCX - Free Report) . Here's why both are grabbing headlines, and what it means for their long-term positioning.

SpaceX's Record Debut Gets Bigger

SpaceX went public earlier this month in a historic listing, closing its first day of trading at a market cap of $2.1 trillion — the highest valuation ever recorded for a company on its debut. The stock has swung around quite a bit since then, as is typical for a newly listed mega-cap.

The latest catalyst came after markets closed on Friday, when Nasdaq announced SpaceX will join the Nasdaq-100 starting July 7. That's one of the fastest index inclusions in the exchange's history, and it matters because it will trigger buying from index funds that track the Nasdaq-100, creating immediate institutional demand. Shares responded, rising 8% yesterday.

Rocket Lab’s Deal With Iridium

Rocket Lab is making waves with its agreement to acquire Iridium Communications (IRDM Quick QuoteIRDM - Free Report) in a cash-and-stock deal valued at roughly $8 billion. Iridium shareholders set to receive $54 per share. It's one of the largest deals in Rocket Lab's history and is expected to close sometime in mid-2027, pending regulatory approval. RKLB shares jumped 16% yesterday on the news.

The deal combines Rocket Lab's launch and satellite manufacturing capabilities with Iridium's existing satellite communications network, spectrum holdings, and a partner base of more than 500 companies. The result is an end-to-end vertically integrated space company— one that designs, builds, launches, and operates its own satellite constellations while serving customers directly through an established communications network.

With both Rocket Lab and SpaceX making strategic moves to widen their reach, let’s take a closer look at the businesses of both and where they are headed next.

SpaceX's Expanding Empire

SpaceX's business has grown well beyond rockets. Starlink, its satellite internet arm, is now the company's biggest growth engine, fueled by global demand for broadband in underserved regions. Starshield adds a defense and national security revenue stream through government contracts. And following Musk's restructuring, SpaceX now also includes xAI-related operations under its umbrella.

Starlink alone has scale. Partnerships with roughly 30 global mobile network operators position it to deliver direct-to-smartphone voice, text, and data service, tapping into a massive global telecom market. The segment generated over $11.4 billion in revenues and $4.4 billion in operating income last fiscal year.

Starship is the company's biggest long-term catalyst. Having completed its 12th test flight in May 2026, Starship is designed to carry far heavier payloads than Falcon 9, enabling mass deployment of full-sized Starlink satellites and a sharp drop in the cost per gigabit of bandwidth delivered.

Musk has also floated the idea of space-based data centers, which would sidestep regulatory hurdles and take advantage of cheap solar power and natural cooling in orbit. In the meantime, SpaceX is already monetizing compute through its xAI assets— including a deal to lease "Colossus 1" supercomputer capacity to Anthropic, reportedly worth $15 billion a year.

Rocket Lab's Vertical Integration Push

Beyond the Iridium deal, Rocket Lab has been steadily transforming itself from a niche rocket launch provider into a broader space infrastructure company. Its Electron rocket program built an operational track record, and the company has since expanded into spacecraft manufacturing, satellite components, mission software and systems integration. That diversification means the business no longer leans solely on launch revenues.

A key growth driver ahead is the Neutron rocket, aimed at the medium-lift launch market currently dominated by larger players like SpaceX. If Neutron delivers, it could open up a much bigger addressable market for Rocket Lab, while partial reusability should help economics.

The company has also been adding capabilities through acquisitions, including Motiv Space Systems (now Rocket Lab Robotics), which strengthens its robotics and spacecraft mechanism offerings for missions ranging from planetary exploration to national security work.

Rising defense demand— particularly around responsive launch and missile defense — adds another growth lever. A solid balance sheet gives the company room to keep funding Neutron and pursuing further deals.

Rocket Lab & SpaceX Growth Comparison  

Per the Zacks Consensus Estimate, SpaceX’s top line is expected to expand 164% this year to $37 billion, up from $18.7 billion in 2025. Sales for 2027 are projected to climb another 101% to $75 billion.

The Zacks Consensus currently calls for SpaceX to post an adjusted loss of $1.19 per share in 2026, with a much narrower loss of 9 cents per share expected next year.

Image Source: Zacks Investment Research

Based on the Zacks Consensus Estimate, Rocket Labs’ annual sales are expected to increase 55% this year and another 35% in fiscal 2027 to $1.26 billion.

Its loss per share is currently pegged at 12 cents for this year, narrower than 27 cents incurred in 2025. Next year, loss per share is estimated to narrow further to 3 cents.

Image Source: Zacks Investment Research

SPCX Has the Edge

Both RKLB and SPCX currently have a Zacks Rank #3 (Hold), meaning each is worth retaining for investors who already own shares. Having said that, SpaceX has the edge. Yes, its losses are deeper and the valuation already demands strong execution, but SpaceX sits at the intersection of several long-term secular trends — space infrastructure, global communications, defense modernization, and artificial intelligence. If management delivers on the vision, today's businesses could end up being just a fraction of the company’s eventual earnings power.

You can see the complete list of today’s Zacks #1 Rank (Strong Buy) stocks here.